Exhibit 31.1
Certification of Chief Executive Officer Pursuant to Section 302 of the
Sarbanes Oxley Act

I, Michael R. Sand, certify that:

1.  I have reviewed this Form 10-Q of Timberland Bancorp, Inc.;

2.  Based on my knowledge, this report does not contain any untrue statement of
    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 officer(s) 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 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 officer(s) 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 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: February 5, 2009
                                       /s/Michael R. Sand
                                       --------------------
                                       Michael R. Sand
                                       Chief Executive Officer
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