Exhibit 5.1

Opinion of Hall, Estill, Hardwick, Gable, Golden & Nelson, P.C.

September 30, 2022

ADDvantage Technologies Group, Inc.

1430 Bradley Lane

Carrollton, TX 75007

Re: REGISTRATION STATEMENT ON FORM S-8

Ladies and Gentlemen:

We have examined the Registration Statement on Form S‑8 (the “Registration Statement”), to be filed by you with the Securities and Exchange Commission in connection with the registration under the Securities Act of 1933, as amended, of 1,000,000 additional shares of your Common Stock (the “Shares”) issued or issuable upon the exercise of options granted under the 2015 Incentive Stock Plan, as amended (“Plan”) referred to therein. As your counsel in connection with this transaction, we have examined the proceedings taken and proposed to be taken by you in connection with the issuance of the Shares.

It is our opinion that the Shares, when issued and paid for in accordance with the terms of the Plan, will be legally and validly issued, fully paid, and nonassessable.

We consent to the use of this opinion as an exhibit to the Registration Statement, including the prospectus constituting a part thereof, and any amendment thereto.

Very truly yours,

/s/ Hall, Estill, Hardwick, Gable, Golden & Nelson, P.C.

HALL, ESTILL, HARDWICK, GABLE,

GOLDEN & NELSON, P.C.