Exhibit 5.1

May 18, 2017

Autodesk, Inc.

111 McInnis Parkway,

San Rafael, California 94903

Re: Registration Statement on Form S-3

Ladies and Gentlemen:

We have acted as counsel to Autodesk, Inc., a Delaware corporation (the “Company”), in connection with the filing by the Company with the Securities and Exchange Commission (the “Commission”) of a registration statement on Form S-3 (the “Registration Statement”), under the Securities Act of 1933, as amended (the “Act”), that is automatically effective under the Act pursuant to Rule 462(e) promulgated thereunder. Pursuant to the Registration Statement, the Company is registering under the Act an indeterminate amount of the Company’s senior debt securities (the “Senior Debt Securities”). The Senior Debt Securities are to be sold from time to time as set forth in the Registration Statement, the prospectus contained therein (the “Prospectus”), and the supplements to the Prospectus (the “Prospectus Supplements”).

The Senior Debt Securities are to be issued pursuant to a senior indenture, dated December 13, 2012, which has been incorporated by reference as an exhibit to the Registration Statement (the “Indenture”), entered into between the Company and U.S. Bank National Association, as trustee. The Indenture may be supplemented, as applicable, in connection with the issuance of each such series of Senior Debt Securities, by a supplemental indenture or other appropriate action of the Company creating such series of Senior Debt Securities. The Senior Debt Securities are to be sold pursuant to a purchase, underwriting, subscription or similar agreement approved by the Board of Directors of the Company or a duly constituted and acting committee thereof (such Board of Directors or committee being hereinafter referred to as the “Board”) in substantially the respective forms to be filed under a Current Report on Form 8-K. The Senior Debt Securities are to be issued in the forms included in the Indenture filed as exhibits to the Registration Statement.

We have examined the Registration Statement, the Indenture and such other instruments, documents, certificates and records that we have deemed relevant and necessary for the basis of our opinions hereinafter expressed. In such examination, we have assumed: (i) the authenticity of original documents and the genuineness of all signatures; (ii) the conformity to the originals of all documents submitted to us as copies; (iii) the truth, accuracy and completeness of the information, representations and warranties contained in the instruments, documents, certificates and records we have reviewed; (iv) that the Registration Statement, and any amendments thereto (including post-effective amendments), will have become effective under the Act; (v) that a Prospectus Supplement will have been filed with the Commission describing the Senior Debt Securities offered thereby; (vi) that the Senior Debt Securities will be issued and sold in compliance with applicable U.S. federal and state securities laws and in the manner stated in the Registration Statement and the applicable Prospectus Supplement; (vii) that a definitive purchase, underwriting, subscription or similar agreement with respect to any Senior Debt Securities offered will have been duly authorized and validly executed and delivered by the Company and the other parties thereto; and (viii) the legal capacity of all natural persons. As to any facts material to the opinions expressed herein that were not independently established or verified, we have relied upon oral or written statements and representations of officers and other representatives of the Company.

Autodesk, Inc.

May 18, 2017

Page 2 of 2

Based on such examination, we are of the opinion that:

1. With respect to Senior Debt Securities to be issued under the Indenture, when: (a) the Trustee is qualified to act as Trustee under the Indenture and the Company has filed a Form T-1 for the Trustee with the Commission; (b) the Trustee has duly executed and delivered the Indenture; (c) the Indenture has been duly authorized and validly executed and delivered by the Company to the Trustee; (d) the Indenture has been duly qualified under the Trust Indenture Act of 1939, as amended; (e) the Board has taken all necessary corporate action to approve the issuance and terms of such Senior Debt Securities, the terms of the offering thereof and related matters; and (f) such Senior Debt Securities have been duly executed, authenticated, issued and delivered in accordance with the provisions of the Indenture and the applicable definitive purchase, underwriting, subscription or similar agreement approved by the Board, such Senior Debt Securities will constitute valid and binding obligations of the Company, enforceable against the Company in accordance with their terms.

Our opinion that any document is legal, valid and binding is qualified as to:

(a) limitations imposed by bankruptcy, insolvency, reorganization, arrangement, fraudulent conveyance, moratorium or other laws relating to or affecting the rights of creditors generally;

(b) rights to indemnification and contribution, which may be limited by applicable law or equitable principles; and

(c) general principles of equity, including without limitation concepts of materiality, reasonableness, good faith and fair dealing, and the possible unavailability of specific performance or injunctive relief and limitation of rights of acceleration, regardless of whether such enforceability is considered in a proceeding in equity or at law.

We express no opinion as to the laws of any other jurisdiction, other than the Federal laws of the United States of America, the State of New York as to the enforceability of the Senior Debt Securities, and the General Corporation Law of the State of Delaware.

We hereby consent to the filing of this opinion as an exhibit to the above-referenced Registration Statement and to the use of our name wherever it appears in the Registration Statement, the Prospectus, any Prospectus Supplement, and in any amendment or supplement thereto. In giving such consent, we do not believe that we are “experts” within the meaning of such term as used in the Act or the rules and regulations of the Commission issued thereunder with respect to any part of the Registration Statement, including this opinion as an exhibit.

Very truly yours,

/s/ Wilson Sonsini Goodrich & Rosati, P.C.

WILSON SONSINI GOODRICH & ROSATI

Professional Corporation