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 2020

Commission File Number: 001-36515

Materialise NV

Technologielaan 15

3001 Leuven

Belgium

(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):  ☐

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):  ☐

On November 30, 2020, Materialise NV (the “Company” or “Materialise”) announced that it will hold an extraordinary shareholders’ meeting on December 31, 2020 at 10:30 a.m., Central European Time. This meeting is being held at the request of Ailanthus NV (a company fully owned by Wilfried Vancraen and Hilde Ingelaere, hereafter “Ailanthus”), of Wilfried Vancraen and of Hilde Ingelaere. The purpose of the meeting is to decide on the previously announced merger between Ailanthus and Materialise.

More information about the proposed merger can be found in the Company’s earlier Report on Form 6-K, which was furnished to the Securities and Exchange Commission on November 17, 2020, as well as in the materials pertaining to the extraordinary shareholders’ meeting (including the reports prepared by the board of directors of the Company and the Company’s statutory auditor), which are available on Materialise’s website at http://investors.materialise.com on the Governance page.

The extraordinary general meeting will be held at the offices of notary Stijn Raes, located at Kortrijksesteenweg 1147, 9051 Ghent.

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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.

Date: November 30, 2020

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Exhibit 99.1

Materialise to Hold Special and Extraordinary General Shareholders’ Meeting on December 31, 2020

Leuven, Belgium—November 30, 2020—Materialise NV (NASDAQ:MTLS), a leading provider of additive manufacturing software and of sophisticated 3D printing solutions, today announced that it will host an extraordinary general shareholders’ meeting at 10:30 AM CET on Thursday, December 31, 2020.

The event will be held at the offices of notary Stijn Raes, located at Kortrijksesteenweg 1147, 9051 Ghent. Due to the COVID-19 pandemic, Materialise will offer the possibility to attend the meetings electronically and recommends that the security holders that wish to participate in the meetings make, as much as practically possible, use of the right to vote by proxy or by voting form. Dial-in details will be provided on http://investors.materialise.com on the Events & Presentations page.

The convening notices and other documents, pertaining to the extraordinary general shareholders’ meeting, including the merger proposal and the report of the board of directors and statutory auditor, are available on Materialise’s website at http://investors.materialise.com on the Governance page.

About Materialise

Materialise incorporates 30 years of 3D printing experience into a range of software solutions and 3D printing services, which together form the backbone of the 3D printing industry. Materialise’s open and flexible solutions enable players in a wide variety of industries, including healthcare, automotive, aerospace, art and design, and consumer goods, to build innovative 3D printing applications that aim to make the world a better and healthier place. Headquartered in Belgium, with branches worldwide, Materialise combines the largest group of software developers in the industry with one of the largest and most complete 3D printing facilities in the world. For additional information, please visit: www.materialise.com.