Exhibit 5.1

October 30, 2002

Board of Directors

Sara Lee Corporation

Three First National Plaza

Chicago, Illinois 60602-4260

Re: Sara Lee Corporation

Registration Statement on Form S-3

Ladies and Gentlemen:

We have served as counsel to Sara Lee Corporation, a Maryland corporation (the “Company”), in connection with its sale and issuance of up to $500,000,000.00 aggregate principal amount of 6 ¹/8% Notes due 2032 (the “Notes”) of the Company, covered by the Registration Statement on Form S-3 filed on March 5, 2002 (Registration No. 333-83776) by the Company with the Securities and Exchange Commission (the “SEC”) pursuant to the Securities Act of 1933, as amended (the “Securities Act”), as amended by Amendment No. 1 thereto filed by the Company with the SEC on May 13, 2002 and by Amendment No. 2 thereto filed by the Company with the SEC on June 4, 2002 (collectively, the “Registration Statement”).

The Notes will be issued under an Indenture (the “Indenture”) between the Company and The Bank of New York as Trustee, pursuant to the Underwriting Agreement, dated October 28, 2002, including Annex A thereto (the “Underwriting Agreement”), by and among the several Underwriters named therein (collectively, the “Underwriters”), and the Company.

In rendering the opinions expressed below, we have examined and relied upon a copy of the Registration Statement and the exhibits filed therewith. We have also examined originals, or copies of originals certified to our satisfaction, of such agreements, documents, certificates and statements of government officials and other instruments, and have examined such questions of law and have satisfied ourselves as to such matters of fact, as we have considered relevant and necessary as a basis for this letter. We have assumed the authenticity of all documents submitted to us as originals, the genuineness of all signatures, the legal capacity of all persons and the conformity with the original documents of any copies thereof submitted to us for examination.

Sara Lee Corporation

October 30, 2002

Page 2

Based on the foregoing, and subject to the qualifications and limitations hereinafter set forth, we are of the opinion that, assuming the Notes have been duly authorized by the Company, when duly executed and authenticated in accordance with the provisions of the Indenture and delivered to and paid for by the Underwriters in accordance with the terms of the Underwriting Agreement, the Notes will be legally issued and binding obligations of the Company enforceable against the Company in accordance with their terms, except to the extent enforceability may be limited by bankruptcy, insolvency, reorganization, moratorium, fraudulent transfer or other similar laws of general applicability relating to or affecting the enforcement of creditors’ rights and by the effect of general principles of equity (regardless of whether enforceability is considered in a proceeding in equity or at law).

This letter is limited to the laws of the State of New York and, to the extent applicable, the federal laws of the United States of America.

We note that a letter of Ballard Spahr Andrews & Ingersoll, LLP, Maryland counsel to the Company, delivered to you concurrently herewith, addresses, among other things, the authorization and execution of the Notes.

We do not find it necessary for the purposes of this letter to cover, and accordingly we express no opinion as to, the application of the securities laws or blue sky laws of the various jurisdictions to the Notes.

We hereby consent to the filing of this letter as Exhibit 5.1.2 to the Registration Statement and the references to our firm included in or made a part of the Registration Statement.

Very truly yours,

/S/    SIDLEY AUSTIN BROWN & WOOD