Exhibit 5.1

Harney Westwood & Riegels Singapore LLP

138 Market Street

#24-04 CapitaGreen

Singapore 048946

Tel: +65 6800 9830

Fax: +65 6800 9831

31 March 2026

lishi.fong@harneys.com

+65 6800 9833

058582.0002/LZF

SIMPPLE LTD.

Harneys Fiduciary (Cayman) Limited

4^th Floor, Harbour Place

103 South Church Street, P.O. Box 10240

Grand Cayman, KY1-1002

Cayman Islands

Dear Sir or Madam

SIMPPLE LTD., Company No. 393431 (the Company)

We are attorneys-at-law qualified to practise in the Cayman Islands and have acted as Cayman Islands legal advisers to the Company in connection with the Form 6-K (as defined in Schedule 1), to be filed on or about the date of this opinion with the U.S. Securities and Exchange Commission (the Commission) under the U.S. Securities Act of 1933, as amended (the Securities Act), relating to the offering, issuance and sale by the Company of 4,000,000 ordinary shares of par value of US$0.0008 each in a private offering (the Offer Shares). The Offer Shares are being offered pursuant to the Prospectus Supplement (defined in Schedule 1) to the Registration Statement (defined in Schedule 1) relating to the offering by the Company of the Offer Shares under the Underwriting Agreement (as defined in Schedule 1). The Company will also be issuing warrants to the underwriters (the Warrants) to purchase up to 300,000 ordinary shares of the Company of par value US$0.0008 each, which is equal to seven and a half percent (7.5%) of the Offer Shares (the Underlying Shares, together with the Offer Shares, the Shares) pursuant to the Warrant Agreement (defined in Schedule 1). In this opinion Companies Act means the Companies Act (2026 Revision) of the Cayman Islands.

We are filing this opinion as Exhibit 5.1 to the Form 6-K which is incorporated by reference to the Registration Statement.

For the purposes of giving this opinion, we have examined the Documents (as defined in Schedule 1). We have not examined any other documents, official or corporate records or external or internal registers and have not undertaken or been instructed to undertake any further enquiry or due diligence in relation to the transaction which is the subject of this opinion.

In giving this opinion we have relied upon the assumptions set out in Schedule 2 which we have not verified.

Jersey legal services are provided through a referral arrangement with Harneys (Jersey) which is an independently owned and controlled Jersey law firm.

Registered in Singapore with limited liability (T13LL2450G).

615409462.6

Anguilla | Bermuda | British Virgin Islands

Cayman Islands | Cyprus | Dubai | Hong Kong |

Jersey London | Luxembourg | Shanghai | Singapore

harneys.com

Based solely upon the foregoing examinations and assumptions and upon such searches as we have conducted and having regard to legal considerations which we deem relevant, and subject to the qualifications set out in Schedule 3, we are of the opinion that under the laws of the Cayman Islands:

Existence and Good Standing. The Company is an exempted company duly incorporated with limited liability, and is validly existing and in good standing under the laws of the Cayman Islands, with power and authority (corporate and other) to own its properties and conduct its business as described in the Registration Statement. It is a separate legal entity and is subject to suit in its own name.

2	Valid Issuance of Shares. The allotment and issuance by the Company of the Shares have been duly authorised by the Company by the Resolutions (as defined in Schedule 1) and, subject to the satisfaction of any conditions or requirements set forth in the Agreements (as defined in Schedule 1), will be validly and legally issued and allotted and credited as fully paid and non-assessable.

3	Warrant Agreement. The Warrant Agreement, when executed and delivered in accordance with the Resolutions and subject to the satisfaction of any conditions or requirements set forth therein, will be treated by the courts of the Cayman Islands as the legally binding and valid obligations of the Company enforceable in accordance with its terms.

4	Authorised Share Capital. Based on the M&A (as defined in Schedule 1), the Company has an authorised share capital of US$3,200,000 divided into 4,000,000,000 ordinary shares of par value of US$0.0008 each of such class or classes (however designated) as the board of directors may determine.

This opinion is confined to the matters expressly opined on herein and given on the basis of the laws of the Cayman Islands as they are in force and applied by the Cayman Islands courts at the date of this opinion. We have made no investigation of, and express no opinion on, the laws of any other jurisdiction. We express no opinion as to matters of fact.

In connection with the above opinion, we hereby consent to the filing of this opinion as an exhibit to the Form 6-K which is incorporated by reference to the Registration Statement and references to our name under the caption “Legal Matters” in the Prospectus Supplement. In giving such consent, we do not thereby admit that we come within the category of persons whose consent is required under Section 7 of the Securities Act, as amended, or the Rules and Regulations of the Commission thereunder.

This opinion is limited to the matters referred to herein and shall not be construed as extending to any other matter or document not referred to herein.

This opinion shall be construed in accordance with the laws of the Cayman Islands.

Yours faithfully

/s/ Harney Westwood & Riegels Singapore LLP

Harney Westwood & Riegels Singapore LLP

Schedule 1

List of Documents Examined

1	A copy of the certificate of incorporation of the Company dated 24 August 2022.

2	A copy of the amended and restated memorandum and articles of association of the Company as adopted by a special resolution passed on 14 October 2025 (the *M&A*).

3	A copy of the certificate of good standing in respect of the Company issued by the Registrar of Companies dated 30 March 2026.

4	The Register of Writs and other Originating Process of the Grand Court of the Cayman Islands (the *Court Register) via the Court’s Digital System (as defined in Schedule 3) from the incorporation date of the Company to 30 March 2026 (the Court Search Date*).

5	A copy of the written resolutions of the directors of the Company dated 24 October 2025 and 26 March 2026 (the *Resolutions*).

6	A copy of the certificate from a director of the Company dated 27 March 2026 (the *Director’s Certificate*).

7	A copy of the executed underwriting agreement dated 31 March 2026 between the Company and Network 1 Financial Securities, Inc. (the *Underwriting Agreement*).

8	A copy of the draft ordinary purchase warrant for the purchase of 300,000 ordinary shares of the Company to be entered into between the Company and Network 1 Financial Securities, Inc. (the *Warrant Agreement*).

9	A copy of the preliminary prospectus supplement dated 26 March 2026 (the *Prospectus Supplement*).

10	A copy of the prospectus dated 27 October 2025 effective as of 16 November 2025 (the *Prospectus*).

11	A copy of the registration statements on Form F-3 (including all amendments or supplements thereto) (File No. 333-291085) (the *Registration Statement*, which term does not include any other document or agreement whether or not specifically referred to therein or attached as an exhibit or schedule thereto).

12	A copy of the draft Form 6-K relating to the Agreements and the Shares (*Form 6-K*).

1 to 6 above are the Corporate Documents, 7 to 11 above are the Transaction Documents, and 7 and 8 above are the Agreements. The Corporate Documents and the Transaction Documents are collectively referred to in this opinion as the Documents.

Schedule 2

Assumptions

1	Validity under Foreign Laws. That (i) each party to the Agreements (other than the Company) has the necessary capacity, power and authority to enter into the Agreements and perform its obligations thereunder, and each such party has duly executed the Agreements; (ii) the Agreements constitutes valid, legally binding and enforceable obligations of each of the parties thereto under the laws of New York State by which law it is expressed to be governed; (iii) all formalities required under the laws of New York State and any other applicable laws (other than the laws of the Cayman Islands) have been complied with; and (iv) no other matters arising under any foreign law will affect the views expressed in this opinion.

2	Draft Documents. That the Company will duly execute and deliver the Warrant Agreement in the form of the draft provided to us for review.

3	Choice of Laws. The choice of the laws of the State of New York selected to govern the Agreements has been made in good faith and will be regarded as a valid and binding selection which will be upheld in the courts of that jurisdiction and all other relevant jurisdictions (other than the Cayman Islands) and the entry into and performance of the Agreements will not cause any of the parties thereto to be in breach of any agreement or undertaking.

4	Memorandum and Articles. The M&A remain in full force and effect and are otherwise unamended. The M&A will be the memorandum and articles of association of the Company in effect at the time of the issue of the Shares.

5	Directors. The board of directors of the Company considers the transactions contemplated by the Transaction Documents to be in the best interests of the Company and no director has a financial interest in or other relationship to a party to the transactions contemplated by the Transaction Documents which has not been properly disclosed in the Resolutions.

6	Conditions. All conditions to the obligations of the parties to the Agreements will be satisfied or duly waived prior to the issue and sale of the Shares and there will be no breach of the terms of the Agreements.

7	Authenticity of Documents. All original Documents are authentic, all signatures, initials and seals are genuine, all copies of Documents are true and correct copies and the Transaction Documents conform in every material respect to the latest drafts of the same produced to us and, where the Transaction Documents have been provided to us in successive drafts marked-up to indicate changes to such documents, all such changes have been so indicated.

8	Corporate Documents. All matters required by law to be recorded in the Corporate Documents are so recorded, and all corporate minutes, resolutions, certificates, documents and records which we have reviewed are accurate and complete, and all facts expressed in or implied thereby are accurate and complete.

9	Director’s Certificate. The contents of the Director’s Certificate are true and accurate as at the date of this opinion.

10	Court Search. The Register of Writs and other Originating Process of the Grand Court of the Cayman Islands examined by us for the period from the date of incorporation of the Company to the Court Search Date via the Court’s Digital System on the Court Search Date, constitutes a complete record of the proceedings for such period before the Grand Court of the Cayman Islands.

11	No Steps to Wind-up. The directors and shareholders of the Company have not taken any steps to have the Company struck off or placed in liquidation, no steps have been taken to wind up the Company and no receiver has been appointed over any of the property or assets of the Company.

12	Resolutions. The written Resolutions have been duly executed (and where by a corporate entity such execution has been duly authorised if so required) by or on behalf of each director or shareholder (as the case may be), and the signatures and initials thereon are those of a person or persons in whose name the Resolutions have been expressed to be signed. The Resolutions passed at a meeting were adopted at duly convened meetings of the board of directors and/or the shareholders of the Company, and such meetings were held and conducted in accordance with the Memorandum and Articles of Association of the Company. The Resolutions remain in full force and effect.

13	Execution. The Agreements were either executed as a single physical document (whether in counterpart or not) in full and final form or, where the Agreements were executed by or on behalf of any company, body corporate or corporate entity, the relevant signature page was attached to the Agreements by, or on behalf of, the relevant person or otherwise with such person’s express or implied authority.

14	Unseen Documents. Save for the Documents provided to us there are no resolutions, agreements, documents or arrangements which materially affect, amend or vary the transactions envisaged in the Transaction Documents. There is no contractual prohibition (other than as arising under Cayman Islands law) binding on the Company prohibiting it from issuing and allotting the Shares.

15	Proceeds of Crime. No monies paid to or for the account of any party under the Transaction Documents represent or will represent criminal property or terrorist property (as defined in the Proceeds of Crime Act (2025 Revision) and the Terrorism Act (2018 Revision), respectively.

16	Exercise. At the time of the exercise of the Warrants in accordance with the M&A (the *Exercise*):

	(a)	the Companies Act will not have changed in such a way as to materially impact the Exercise;

	(b)	the Company will have sufficient authorised but unallotted and unissued Underlying Shares, in each case to effect the Exercise in accordance with the M&A and the Companies Act;

	(c)	the Company will be able to pay its debts as they fall due in the ordinary course of business immediately following the Exercise;

	(d)	the Company will have shares in issue immediately prior to the Exercise other than the Underlying Shares to be issued;

	(e)	all the considerations will have been fully paid and without obligation of the holder to make further payment to the Company in respect of the issuance of the Underlying Shares;

	(f)	the Company will not have been struck off or placed in liquidation;

	(g)	the issue price for the Underlying Shares to be issued on the Exercise will not be less than the par value of such Underlying Shares; and

	(h)	the provisions of the M&A relating to the Exercise will not have been altered, amended and restated.

Schedule 3

Qualifications

Enforceability. The term enforceable as used above means that the obligations assumed by the Company under the relevant instrument are of a type which the courts of the Cayman Islands enforce. It does not mean that those obligations will necessarily be enforced in all circumstances in accordance with their terms. In particular:

	(a)	Insolvency. Rights and obligations may be limited by bankruptcy, insolvency, liquidation, winding-up, reorganisation, moratorium, readjustment of debts, arrangements and other similar laws of general application affecting the rights of creditors;

	(b)	Limitation Periods. Claims under the Agreements may become barred under the Limitation Act (1996 Revision) relating to the limitation of actions in the Cayman Islands or may be or become subject to defences of set-off, estoppel or counterclaim;

	(c)	Equitable Rights and Remedies. Equitable rights may be defeated by a bona fide purchaser for value without notice. Equitable remedies such as injunctions and orders for specific performance are discretionary and will not normally be available where damages are considered an adequate remedy;

	(d)	Fair Dealing. Strict legal rights may be qualified by doctrines of good faith and fair dealing - for example a certificate or calculation as to any matter might be held by a Cayman Islands court not to be conclusive if it could be shown to have an unreasonable or arbitrary basis, or in the event of manifest error;

	(e)	Prevention of Enforcement. Enforcement may be prevented by reason of fraud, coercion, duress, undue influence, unreasonable restraint of trade, misrepresentation, public policy or mistake or limited by the doctrine of frustration of contracts;

	(f)	Penal Provisions. Provisions, for example, for the payment of additional interest in certain circumstances, may be unenforceable to the extent a court of the Cayman Islands determines such provisions to be penal;

	(g)	Currency. A Cayman Islands court retains a discretion to denominate any judgment in Cayman Islands dollars;

	(h)	Confidentiality. Provisions imposing confidentiality obligations may be overridden by the requirements of legal process;

	(i)	Award of Costs. In principle the courts of the Cayman Islands will award costs and disbursements in litigation in accordance with the relevant contractual provisions but there remains some uncertainty as to the way in which the rules of the Grand Court will be applied in practice. Whilst it is clear that costs incurred prior to judgment can be recovered in accordance with the relevant contract, it is likely that post-judgment costs (to the extent recoverable at all) will be subject to taxation in accordance with Grand Court Rules Order 62; and

	(j)	Inappropriate Forum. The courts of the Cayman Islands may decline to exercise jurisdiction in relation to substantive proceedings brought under or in relation to the Agreements in matters where they determine that (i) such proceedings may be tried in a more appropriate forum; (ii) proceedings are already underway in a different forum; or (iii) the issues have already been finally determined by another forum.

2	Foreign Statutes. We express no opinion in relation to provisions making reference to foreign statutes in the Transaction Documents.

3	Stamp Duty. Cayman Islands stamp duty may be payable if an original of the Agreements is executed in, brought to, or produced before a court of, the Cayman Islands.

4	Several Remedies. In certain circumstances provisions in the Agreements that (i) the election of a particular remedy does not preclude recourse to one or more others; or (ii) delay or failure to exercise a right or remedy will not operate as a waiver of any such right or remedy, may not be enforceable.

5	Exculpation and Indemnity Provisions. The effectiveness of terms in the Agreements excusing any party from a liability or duty otherwise owed or indemnifying that party from the consequences of incurring such liability or breaching such duty are limited by law.

6	Commercial Terms. Except as specifically stated herein, we make no comment with respect to any representations and warranties which may be made by or with respect to the Company in any of the documents or instruments cited in this opinion or otherwise with respect to the commercial terms of the transactions the subject of this opinion.

7	Meaning of Non-Assessable. In this opinion the phrase non-assessable means, with respect to the issuance of shares, that a shareholder shall not, in respect of the relevant shares, have any obligation to make further contributions to the assets of the relevant company (except in exceptional circumstances, such as involving fraud, the establishment of an agency relationship or an illegal or improper purpose or other circumstances in which a court may be prepared to pierce or lift the corporate veil).

8	Amendment. A Cayman Islands court would not treat as definitive a statement in a contract that it could only be amended or waived in writing, but would be able to consider all the facts of the case (particularly where consideration had passed) to determine whether a verbal amendment or waiver had been effected and, if it found that it had, such verbal amendment or waiver would be deemed to have also amended the stated requirement for a written agreement.

9	Good Standing. The Company shall be deemed to be in good standing at any time if all fees (including annual filing fees) and penalties under the Companies Act have been paid and the Registrar of Companies has no knowledge that the Company is in default under the Companies Act.

10	Court Search. The search of the Register of Writs and other Originating Process of the Grand Court of the Cayman Islands has been undertaken on a digital system made available through the Grand Court of the Cayman Islands (the *Court’s Digital System), and through inadvertent errors or delays in updating the digital system (and/or the Register from which the digital information is drawn) may not constitute a complete record of all proceedings as at the Court Search Date and in particular may omit details of very recent filings. The Court Search of the Court Register would not reveal, amongst other things, any writ, originating summons, originating motion, petition (including any winding-up petition), counterclaim or third party notice (Originating Process*) filed with the Grand Court of the Cayman Islands which, pursuant to the rules of the Grand Court of the Cayman Islands or best practice of the Clerk of the Courts’ office, should have been entered in the Court Register but was not in fact entered in the Court Register (properly or at all), or any Originating Process which has been placed under seal or anonymised (whether by order of the Court or pursuant to the practice of the Clerk of the Courts’ office).

11	Conflict of Laws. An expression of an opinion on a matter of Cayman Islands law in relation to a particular issue in this opinion should not necessarily be construed to imply that the Cayman Islands courts would treat Cayman Islands law as the proper law to determine that issue under its conflict of laws rules.

12	Sanctions. The obligations of the Company may be subject to restrictions pursuant to United Nations and United Kingdom sanctions as implemented under the laws of the Cayman Islands.

13	Economic Substance. We have undertaken no enquiry and express no view as to the compliance of the Company with the International Tax Co-operation (Economic Substance) Act (2026 Revision).

SIMPPLE LTD. 6-K