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): April 20, 2026

KPET Ultra Paceline Corporation

(Exact name of registrant as specified in its charter)

605-308-0233
(Registrant’s telephone number, including area code)

Not Applicable
(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

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

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 8.01 Other Events.

As previously disclosed, on April 1, 2026, KPET Ultra Paceline Corporation (the “Company”) completed its initial public offering (the “IPO”) of 20,000,000 units (the “IPO Units”). On April 15, 2026, the underwriter of the Company’s IPO exercised its over-allotment option in full and on April 20, 2026, the underwriter purchased an additional 3,000,000 units (the “Option Units”). Each Option Unit consists of one Class A ordinary share of the Company, par value $0.0001 per share (the “Class A Ordinary Shares”), and one-sixth of one warrant of the Company, each whole warrant entitling the holder thereof to purchase one Class A Ordinary Share at a price of $11.50 per share. The Option Units were sold at a price of $10.00 per unit, generating gross proceeds to the Company of $30,000,000.

As previously disclosed, on April 1, 2026, simultaneously with the consummation of the IPO, the Company completed the private sale (the “Private Placement”) of 235,000 units (the “Private Placement Units”) at a purchase price of $10.00 per Private Placement Unit to KPET Ultra Paceline Unit Holdings, LLC, generating gross proceeds to the Company of $2,350,000.

Of the net proceeds of the IPO, the sale of the Private Placement Units and the sale of the Option Units, a total of $230,000,000, including $12,650,000 of deferred underwriting discounts and commissions, was placed in a trust account with Continental Stock Transfer & Trust Company acting as trustee.

An unaudited balance sheet as of April 20, 2026 reflecting receipt of the proceeds from the consummation of the IPO, the Private Placement and the underwriter’s full exercise of its over-allotment option, has been issued by the Company and is included as Exhibit 99.1 to this Current Report on Form 8-K.

Item 9.01 Financial Statements and Exhibits.

SIGNATURES

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