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): June 5, 2025

DUKE ENERGY OHIO, INC.

(Exact Name of Registrant as Specified in its Charter)

Ohio		1-1232		31-0240030
(State or Other Jurisdiction of Incorporation)		(Commission File Number)		(IRS Employer Identification No.)

139 East Fourth Street, Cincinnati, Ohio 45202

(Address of Principal Executive Offices, including Zip code)

(800) 488-3853

(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:

¨ 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 CFR 240.14a-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. 13e-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
	None

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.

On June 5, 2025, Duke Energy Ohio, Inc. (the “Company”) consummated the issuance and sale of the securities described below pursuant to an underwriting agreement, dated June 2, 2025 (the “Underwriting Agreement”), with BMO Capital Markets Corp., CIBC World Markets Corp., Mizuho Securities USA LLC and SMBC Nikko Securities America, Inc., as representatives of the several underwriters named therein (the “Underwriters”), pursuant to which the Company agreed to issue and sell to the Underwriters $350,000,000 aggregate principal amount of the Company’s First Mortgage Bonds, 5.30% Series, Due June 15, 2035 (the “Bonds”). The Bonds were sold to the Underwriters at a discount to their principal amount. The Bonds will be issued under the First Mortgage, dated as of August 1, 1936, between the Company and The Bank of New York Mellon Trust Company, N.A., as trustee, as amended and supplemented from time to time (the “Indenture”), including by the Fiftieth Supplemental Indenture, dated as of June 5, 2025 (the “Supplemental Indenture”). The disclosure in this Item 8.01 is qualified in its entirety by the provisions of the Indenture, the Supplemental Indenture, which together with the form of global bond evidencing the Bonds, is filed as Exhibit 4.1 hereto, and the Underwriting Agreement, which is filed as Exhibit 99.1 hereto. Such exhibits are incorporated herein by reference. Also, in connection with the issuance and sale of the Bonds, the Company is filing a legal opinion regarding the validity of the Bonds as Exhibit 5.1 to this Form 8-K for the purpose of incorporating the opinion into the Company’s Registration Statement (File No. 333-267583-05).

Item 9.01.

Financial Statements and Exhibits.

(d)

Exhibits

4.1

Fiftieth Supplemental Indenture, dated as of June 5, 2025, between the Company and The Bank of New York Mellon Trust Company, N.A., as trustee, and form of global bond.

5.1

Opinion regarding validity of the Bonds.

23.1

Consent (included as part of Exhibit 5.1).

99.1

Underwriting Agreement, dated June 2, 2025, among the Company and BMO Capital Markets Corp., CIBC World Markets Corp., Mizuho Securities USA LLC and SMBC Nikko Securities America, Inc., as representatives of the several underwriters named therein, in connection with the Company’s issuance and sale of the Bonds.

104

Cover Page Interactive Data File – the cover page XBRL tags are embedded within the Inline XBRL document.

SIGNATURE

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

	DUKE ENERGY OHIO, INC.

Date: June 5, 2025	By:	/s/ Elizabeth H. Jones
		Name:	Elizabeth H. Jones
		Title:	Deputy General Counsel and Assistant Corporate Secretary

Duke Energy Ohio, Inc. 8-K