1
                                                                     EXHIBIT 5.1




                                October 30, 1997

Noble Affiliates, Inc.
110 West Broadway
Ardmore, Oklahoma  73401

Dear Sirs:

         We have acted as counsel for Noble Affiliates, Inc., a Delaware
corporation (the "Company"), in connection with the registration under the
Securities Act of 1933, as amended (the "Securities Act"), of 2,000,000 shares
(the "Shares") of common stock, par value $3.33 1/3 per share, of the Company
for issuance pursuant to the Company's 1992 Stock Option and Restricted Stock
Plan, as amended (the "Plan").

         In connection with the foregoing, we have examined the originals or
copies, certified or otherwise authenticated to our satisfaction, of such
corporate records of the Company, agreements and other instruments,
certificates of public officials and of officers of the Company, and other
instruments and documents as we have deemed necessary to require as a basis for
the opinion hereinafter expressed.  We have also participated in the
preparation of the Company's Registration Statement on Form S-8 (the
"Registration Statement") to be filed with the Securities and Exchange
Commission relating to the registration of the Shares under the Securities Act.

         On the basis of the foregoing, we advise you that, in our opinion, the
Shares have been duly authorized by the Company and, when issued upon the due
exercise of options or stock appreciation rights duly granted under the Plan or
upon the due award as restricted stock under the Plan, will be legally issued,
fully paid and nonassessable.

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

                                        Respectfully submitted,

                                        THOMPSON & KNIGHT,
                                        A Professional Corporation


                                        By:/S/ ROBERT D. CAMPBELL             
                                           -----------------------------------
                                               Robert D. Campbell, Attorney