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                                                                     EXHIBIT 5.1

                        [IRELL & MANELLA LLP LETTERHEAD]


                                  June 4, 2002



Big 5 Sporting Goods Corporation
2525 E. El Segundo Boulevard
El Segundo, CA  90245

         Re: Registration Statement 333-68094; up to 7,700,000 shares of
             common stock, par value $0.01 per share

Ladies and Gentlemen:

         We have acted as counsel to Big 5 Sporting Goods Corporation, a
Delaware corporation (the "Company"), in connection with the proposed issuance
and sale by the Company of up to 6,113,343 shares of the Company's Common Stock
(the "Company Shares") and the sale by certain Selling Stockholders of up to
1,586,657 shares of the Company's Common Stock (the "Selling Stockholder
Shares") pursuant to the Company's Registration Statement on Form S-1 (the
"Registration Statement") filed with the Securities and Exchange Commission (the
"Commission") on August 21, 2001 (File No. 333-68094), as amended by Amendment
No. 1 filed with the Commission on March 17, 2002 and Amendment No. 2 filed with
the Commission on June 4, 2002 (collectively, the "Registration Statement")
under the Securities Act of 1933, as amended (the "Act").

         This opinion is being furnished in accordance with the requirements of
Item 16(a) of Form S-1 and Item 601(b)(5)(i) of Regulation S-K.

         In our capacity as counsel to the Company in connection with such
registration, we are familiar with the proceedings taken by the Company in
connection with the authorization, issuance and sale of the Company Shares and
the sale of the Selling Stockholder Shares. In addition, we have made such legal
and factual examinations and inquiries, including an examination of originals or
copies certified or otherwise identified to our satisfaction of such documents,
corporate records and instruments, as we have deemed necessary or appropriate
for purposes of this opinion.

         In our examination, we have assumed the genuineness of all signatures,
the authenticity of all documents submitted to us as originals, and the
conformity to authentic original documents of all documents submitted to us as
copies.



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Big 5 Sporting Goods Corporation
June 4, 2002
Page 2



         We are opining herein as to the effect on the subject transaction only
of the General Corporation Law of the State of Delaware, and we express no
opinion with respect to the applicability thereto, or the effect thereon, of the
laws of any other jurisdiction or, in the case of Delaware, any other laws, or
as to any matters of municipal law or the laws of any local agencies within any
state.

         Based on and subject to the foregoing, it is our opinion that (i) the
Company Shares and Selling Stockholder Shares have been duly authorized and (ii)
the Company Shares, upon issuance, delivery and payment therefor in the manner
contemplated by the Registration Statement (as amended and supplemented through
the date of issuance), will be validly issued, fully paid and nonassessable.

         We consent to your filing this opinion as an exhibit to the
Registration Statement and to the reference to our firm contained under the
heading "Legal Matters." In giving this consent, we do not thereby admit that we
are within the category of persons whose consent is required under Section 7 of
the Act, the rules and regulations of the Commission promulgated thereunder, or
Item 509 of Regulation S-K.

         This opinion letter is rendered as of the date first written above and
we disclaim any obligation to advise you of facts, circumstances, events or
developments which hereafter may be brought to our attention and which may
alter, affect or modify the opinion expressed herein. Our opinion is expressly
limited to the matters set forth above and we render no opinion, whether by
implication or otherwise, as to any other matters relating to the Company, the
Company Shares or the Selling Stockholder Shares.


                                       Very truly yours,


                                       /s/  Irell & Manella LLP
                                       -----------------------------------------
                                      IRELL & MANELLA LLP


