
<PAGE>   1
                                                                     EXHIBIT 5.1


<TABLE>
<S>                                       <C>                                           <C>
LAW OFFICES OF                             ___________________________________________________________________________________

LOCKE PURNELL RAIN HARRELL                 2200 ROSS AVENUE . SUITE 2200                  AUSTIN OFFICE:
                                           DALLAS . TEXAS 75201-6776                      515 CONGRESS AVENUE . SUITE 2500
(A PROFESSIONAL CORPORATION)               (214) 740-8000                                 AUSTIN . TEXAS 78701-3500
                                           FAX: (214) 740-8800                            (512) 305-4700
                                           TELEX: 73-0911 LOCKE DAL                             .
                                                                                          NEW ORLEANS OFFICE:
                                                                                          601 POYDRAS STREET . SUITE 2400
                                           WRITER'S DIRECT DIAL NUMBER                    NEW ORLEANS . LOUISIANA 70130-6036
                                                                                          (504) 558-5100

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                                 July 31, 1995

A. H. Belo Corporation
Communications Center
400 South Record Street
Dallas, Texas 75202


         Re:     Registration of 25,000 shares of Common Stock, par value
                 $1.67, pursuant to a Registration Statement on Form S-8


Ladies and Gentlemen:

         We have acted as counsel for A. H. Belo Corporation, a Delaware
corporation (the "Company"), in connection with the registration under the
Securities Act of 1933, as amended (the "Securities Act"), pursuant to a
Registration Statement on Form S-8 (the "Registration Statement"), of 25,000
shares of Series A Common Stock, par value 1.67 per share, of the Company (the
"Common Stock") to be offered to employees of the Company (including its direct
or indirect subsidiaries) pursuant to the A. H. Belo Corporation Employee
Thrift Plan (the "Plan").

         Based upon our examination of such papers and documents as we have
deemed relevant or necessary in rendering this opinion, and based on our review
of the Delaware General Corporation Law, we hereby advise you that we are of
the opinion that assuming, with respect to shares of Common Stock issued after
the date hereof, (i) the receipt of proper consideration for the issuance
thereof in excess of the par value thereof, (ii) the availability of a
sufficient number of shares of Common Stock authorized by the Company's
Certificate of Incorporation then in effect, (iii) compliance with the terms of
any agreement entered into in connection with any options or shares of Common
Stock issued or allocated in connection with the Plan, and (iv) no change
occurs in the applicable law or the pertinent facts, shares of Common Stock
allocable to participants' accounts under the Plan will be legally issued,
fully paid and non-assessable shares of Common Stock.

<PAGE>   2
A. H. Belo Corporation
July 31, 1995
Page 2


         We consent to the filing of this opinion as Exhibit 5.1 to the
Registration Statement filed by the Company with the Securities and Exchange
Commission.  By so consenting, we do not thereby admit that our firm's consent
is required by Section 7 of the Securities Act.

                                             Very truly yours,

                                             LOCKE PURNELL RAIN HARRELL
                                             (A Professional Corporation)


                                             By: /s/ GUY KERR
                                                 --------------------------
                                                 Guy Kerr
