Report of Foreign Issuer (6-k)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of: November 2018

Commission File Number: 001-36563

Orion Engineered Carbons S.A.

(Translation of registrant’s name into English)

6, Route de Trèves

L-2633 Senningerberg (Municipality of Niederanven)

Grand Duchy of Luxembourg

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F x Form 40-F o

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): o

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): o

On November 1, 2018, Orion Engineered Carbons S.A. (the “Company”) released its Unaudited Interim Condensed Financial Statements as at September 30, 2018, which are attached as Exhibit 99.1 hereto and are incorporated by reference into the Company’s Registration Statement on Form F-3 (File No. 333-209963).

SIGNATURE

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, thereunto duly authorized.