Exhibit 23(a)

            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM


We consent to the reference to our firm under the caption "Experts" in the
Registration Statement (Form S-3, No. 333-124502) and the related Prospectus of
Southwest Bancorp, Inc. for the registration of 2,415,000 shares of its common
stock and to the incorporation by reference therein to our reports dated March
14, 2005 with respect to the consolidated financial statements of Southwest
Bancorp, Inc., Southwest Bancorp, Inc. management's assessment of the
effectiveness of internal control over financial reporting, and the
effectiveness of internal control over financial reporting of Southwest Bancorp
included in its Annual Report (Form 10-K) for the year ended December 31, 2004,
filed with the Securities and Exchange Commission.


/s/ Ernst & Young, LLP


Tulsa, Oklahoma
May 17, 2005