Exhibit 5.1

October 13, 2021

Apogee Enterprises, Inc.

4400 West 78th Street, Suite 520

Minneapolis, Minnesota 55435

Re: Registration Statement on Form S-8

Ladies and Gentlemen:

We have acted as counsel to Apogee Enterprises, Inc., a Minnesota corporation (the “Company”), in connection with a Registration Statement on Form S-8 (the “Registration Statement”) filed by the Company with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Securities Act”), relating to the registration of the offer and sale by the Company of up to $5,000,000 of deferred compensation obligations (the “Deferred Compensation Obligations”) under the Apogee Enterprises, Inc. 2021 Deferred Compensation Plan for Non-Employee Directors (the “Plan”).

We have examined such documents and have reviewed such questions of law as we have considered necessary or appropriate for the purposes of our opinions set forth below. In rendering our opinions set forth below, we have assumed the authenticity of all documents submitted to us as originals, the genuineness of all signatures and the conformity to authentic originals of all documents submitted to us as copies. We have also assumed the legal capacity for all purposes relevant hereto of all natural persons. As to questions of fact material to our opinions, we have relied upon certificates or comparable documents of officers and other representatives of the Company and of public officials.

Based on the foregoing, we are of the opinion that the Deferred Compensation Obligations have been duly authorized by the Company and, when created in accordance with the terms of the Plan, will be valid and binding obligations of the Company.

Our opinions expressed above are limited to the laws of the State of Minnesota. Our opinions set forth above are subject to the effect of any applicable bankruptcy, insolvency, reorganization, moratorium or similar law relating to or affecting creditors’ rights generally (including, without limitation, fraudulent conveyance laws) and the effect of 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, regardless of whether considered in a proceeding in equity or at law.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement. In giving this consent, we do not admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Commission thereunder.

Very truly yours,

/s/ Dorsey & Whitney LLP

RAR

50 South Sixth Street | Suite 1500 | Minneapolis, MN | 55402-1498 | T 612.340.2600 | F 612.340.2868 | dorsey.com