Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the use in this Registration Statement on Form S-1 of our
report dated June 30, 2006, with the exception of Note 11, as to which the date
is September 1, 2006, relating to the consolidated financial statements and
financial statement schedule of Isilon Systems, Inc., which appears in such
Registration Statement. We also consent to the reference to us under the heading
"Experts" in such Registration Statement.

/s/ PricewaterhouseCoopers LLP

Seattle, Washington
September 1, 2006