Exhibit 31.1

CERTIFICATION

I, Paul D. Geraghty, President, Chief
Executive Officer and Director, certify, that:

|1. |  | I have reviewed this annual
      report on Form 10-K of Harleysville National Corporation.                                                                                                                                                                                                                                                                       
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|2. |  | Based on my knowledge, the annual
      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 annual report.                   
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|3. |  | Based on my knowledge, the
      financial statements, and other financial information included in this
      annual 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 annual report.                                     
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|4. |  | The registrants other certifying
      officer 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:
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| | (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;         
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| | (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;                
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| | (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                                                                                                          
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| | (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 reasonable likely to materially affect, the registrants internal
      control over financial reporting; and
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|5. |  | The registrants other certifying
      officer 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):
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| | (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
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| | (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: March 7, 2008
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|By: | /s/ Paul D.
      Geraghty                      | 
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|    | President, Chief Executive Officer and Director
|    | Harleysville National Corporation              

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