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                                                                     EXHIBIT 5.1


                   [LETTERHEAD OF BOND, SCHOENECK & KING, LLP]

October 19, 2000

Community Bank Systems, Inc.
5790 Widewaters Parkway
DeWitt, New York 13214

         Re:  Community Bank System, Inc./Registration Statement on Form S-4

Ladies and Gentlemen:

We have acted as counsel to Community Bank System, Inc., a Delaware corporation
(the "Company"), in connection with the preparation and filing of a registration
statement on Form S-4 (the "Registration Statement") under the Securities Act of
1933, as amended, covering an aggregate of 952,000 shares (the "Shares") of
common stock, no par value, of the Company to be issued pursuant to the merger
described in the Registration Statement (the "Merger").

As such counsel, we have examined the Registration Statement and the Agreement
and Plan of Merger, dated September 26, 2000, by and among the Company,
Community Bank, N.A., and The Citizens National Bank of Malone (the "Merger
Agreement") relating to the Merger, as well as such corporate records,
certificates and other documents and such questions of law as we have considered
necessary or appropriate for the purposes of this opinion. In rendering this
opinion, we have (a) assumed (i) the genuineness of all signatures on all
documents examined by us, (ii) the authenticity of all documents submitted to us
as originals, and (iii) the conformity to original documents of all documents
submitted to us as photostatic or conformed copies and the authenticity of the
originals of such copies; and (b) relied on (1) certificates of public officials
and (2) as to matters of fact, statements and certificates of officers of the
Company.

Based on the foregoing, we are of the opinion that the Shares have been duly
authorized and, when issued to the holders of common stock, par value $0.625 per
share, of The Citizens National Bank of Malone in accordance with the Merger
Agreement, the Shares will be validly issued, fully paid and non-assessable.

We are attorneys admitted to the Bar of the State of New York, and express no
opinion as to the laws of any jurisdiction other than the laws of the United
States of America and the State of Delaware.
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We consent to the filing of this opinion as an exhibit to the Registration
Statement and to the use of our name under the heading "Legal Matters" in the
proxy statement/prospectus forming a part of the Registration Statement. In
giving such consent we do not thereby concede that we are within the category of
persons whose consent is required under Section 7 of the Securities Act or the
rules or regulations promulgated thereunder.

Very truly yours,

/s/ BOND, SCHOENECK & KING, LLP