UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of report (Date of earliest event reported): November 19, 2025

CLEARSIGN TECHNOLOGIES CORPORATION

(Exact name of registrant as specified in charter)

Delaware		001-35521		26-2056298
(State or other jurisdiction of incorporation)		(Commission File Number)		(IRS Employer Identification No.)

8023 E. 63rd Place, Suite 101

Tulsa, Oklahoma 74133

(Address of Principal Executive Offices) (Zip Code)

(918) 236-6461

(Registrant's telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the Registrant under any of the following provisions (see General Instruction A.2 below).

¨	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR240.14a-12)

¨	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)).

¨	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13(e)-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common Stock		CLIR		The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 2.02

Results of Operations and Financial Condition.

To the extent required, the information set forth below in Item 7.01 of this Current Report on Form 8-K is incorporated herein by reference in its entirety.

Item 7.01

Regulation FD Disclosure.

On November 19, 2025, ClearSign Technologies Corporation (the “Company”) issued a press release announcing the results of operations for the quarter ended September 30, 2025 (the “Financial Results”). The press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated by reference in its entirety into this Item 7.01.

Also on November 19, 2025, the Company held a conference call discussing the Financial Results and other business related information. A transcript of this conference call is furnished as Exhibit 99.2 to this Current Report on Form 8-K and is incorporated by reference in its entirety into this Item 7.01.

The information furnished with this Item 7.01, including Exhibits 99.1 and 99.2, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Item 9.01

Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.		Description
99.1**		Press Release, dated November 19, 2025.
99.2**		Transcript of Conference Call held on November 19, 2025.
104*		Cover Page Interactive Data File (embedded within the Inline XBRL document).

* Filed herewith.

** Furnished herewith.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this Current Report to be signed on its behalf by the undersigned hereunto duly authorized.

Dated: November 21, 2025

	CLEARSIGN TECHNOLOGIES CORPORATION

	By:	/s/ Colin James Deller
	Name:	Colin James Deller
	Title:	Chief Executive Officer

ClearSign Technologies Corp 8-K