Report of Foreign Issuer (6-k)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

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

UNDER THE SECURITIES EXCHANGE ACT OF 1934

Report on Form 6-K dated August 17, 2017

(Commission File No. 001-35053)

INTERXION HOLDING N.V.

(Translation of Registrant’s Name into English)

Tupolevlaan 24, 1119 NX Schiphol-Rijk, The Netherlands, +31 20 880 7600

(Address of Principal Executive Office)

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 ☒ Form 40-F ☐

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): ☐

Note: Regulation S-T Rule 101(b)(1) only permits the submission in paper of a Form 6-K if submitted solely to provide an attached annual report to security holders.

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) ): ☐

Note: Regulation S-T Rule 101(b)(7) only permits the submission in paper of a Form 6-K if submitted to furnish a report or other document that the registrant foreign private issuer must furnish and make public under the laws of the jurisdiction in which the registrant is incorporated, domiciled or legally organized (the registrant’s “home country”), or under the rules of the home country exchange on which the registrant’s securities are traded, as long as the report or other document is not a press release, is not required to be and has not been distributed to the registrant’s security holders, and, if discussing a material event, has already been the subject of a Form 6-K submission or other Commission filing on EDGAR.

INFORMATION CONTAINED IN THIS FORM 6-K REPORT

On August 15, 2017, our Chief Executive David Ruberg exercised options covering 100,000 shares of common stock with an exercise price of $14.74 and sold 80,000 shares of common stock of Interxion Holding N.V. acquired from this exercise. The 80,000 shares were sold in the open market between August 15 and August 16, 2017 at prevailing market prices. After giving effect to these transactions, as of August 16, 2017, Mr. Ruberg increased his shareholdings by 20,000 shares to 979,986 shares of common stock.

This Report on Form 6-K is incorporated by reference into (i) the Registration Statement on Form S-8 of the Registrant originally filed with the Securities and Exchange Commission on June 23, 2011 (File No. 333-175099), (ii) the Registration Statement on Form S-8 of the Registrant originally filed with the Securities and Exchange Commission on June 2, 2014 (File No. 333-196447) and (iii) the Registration Statement on Form S-8 of the Registrant originally filed with the Securities and Exchange Commission on May 31, 2017 (File No. 333-218364).

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.