<PAGE>

                                  EXHIBIT 31.1

                               CCFNB BANCORP, INC.

                          CEO CERTIFICATION PURSUANT TO
                               SECTION 302 OF THE
                           SARBANES-OXLEY ACT OF 2002

I, Lance O. Diehl, certify that:

         1        I have reviewed this quarterly report on Form 10-Q of CCFNB
                  Bancorp, Inc.

         2.       Based on my knowledge, this report does not contain any untrue
                  statement of a material fact or omit to state a material fact
                  necessary to make the statements made, in light of the
                  circumstances under which such statements were made, not
                  misleading with respect to the period covered by this report.

         3.       Based on my knowledge, the financial statements, and other
                  financial information included in this report, fairly present
                  in all material respects the financial condition, results of
                  operations and cash flows of the registrant as of, and for,
                  the periods presented in this report;

         4.       The registrant's other certifying officers and I are
                  responsible for establishing and maintaining disclosure
                  controls and procedures (as defined in Exchange Act Rules
                  13a-15(e) and 15d - 15 (e) and internal control over financial
                  reporting (as defined in Exchange act Rules 13a-15(f) and
                  15d-15(f) for the registrant and have:

         (a) Designed such disclosure controls and procedures, or caused such
         disclosure controls and procedures to be designed under our
         supervision, to ensure that material information relating to the
         registrant, including its consolidated subsidiaries, is made known to
         us by others within those entities, particularly during the period in
         which this report is being prepared;

         (b)Designed such internal control over financial reporting, or caused
         such internal control over financial reporting to be designed under our
         supervision, to provide reasonable assurance regarding the reliability
         of financial reporting and the preparation of financial statements for
         external purposes in accordance with generally accepted accounting
         principles:

         (c) Evaluated the effectiveness of the registrant's disclosure controls
         and procedures and presented in this report our conclusions about the
         effectiveness of the disclosure controls and procedures as of the end
         of the period covered by this report based on such evaluation; and

         (d) Disclosed in this report any change in the registrant's internal
         control over financial reporting that occurred during the registrant's
         most recent fiscal quarter (the registrant's fourth fiscal quarter in
         the case of an annual report) that has materially affected, or is
         reasonably likely to materially affect, the registrant's internal
         control over financial reporting; and

         5.       The registrant's other certifying officers and I have
                  disclosed, based on our most recent evaluation of internal
                  control over financial reporting, to the registrant's auditors
                  and the audit committee of the registrant's board of directors
                  (or persons performing the equivalent functions):

         (a)      All significant deficiencies and material weaknesses in the
                  design or operation of internal control over financial
                  reporting which are reasonably likely to adversely affect the
                  registrant's ability to record, process, summarize and report
                  financial information; and

         (b)      Any fraud, whether or not material, that involves management
                  or other employees who have a significant role in the
                  registrant's internal control over financial reporting,

Date: August 8, 2003

                          /s/ Lance O. Diehl
                          ---------------------------------
                              Lance O. Diehl
                              Chief Executive Officer

                                       26