POWER OF ATTORNEY*

I hereby constitute and appoint each of Gail S. Mann, Ryan Darrah and Maite
Garcia signing singly, my true and lawful attorney-in-fact to:

(1)	execute for and on my behalf, in my capacity as an officer and/or director
of Forrester Research, Inc. (the "Company"), Forms 3, 4 and 5 in accordance with
Section 16(a) of the Securities Exchange Act of 1934 and the rules thereunder;
(2)	do and perform any and all acts for and on my behalf that may be necessary
or desirable to complete and execute any such Form 3, 4 or 5 and timely file
such form with the United States Securities and Exchange Commission and any
stock exchange or similar authority; and
(3)	take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be to my benefit,
in my best interest, or that I am legally required to do, it being understood
that the documents executed by such attorney-in-fact on my behalf pursuant to
this Power of Attorney shall be in such form and shall contain such terms and
conditions as such attorney-in-fact may approve in such attorney-in-fact's
discretion.

I hereby grant to each such attorney-in-fact full power and authority to do and
perform any and every act and thing whatsoever requisite, necessary, or proper
to be done in the exercise of any of the rights and powers herein granted, as
fully to all intents and purposes as I might or could do if personally present,
with full power of substitution or revocation, hereby ratifying and confirming
all that such attorney-in-fact, or such attorney-in-fact's substitute or
substitutes, shall lawfully do or cause to be done by virtue of this power of
attorney and the rights and powers herein granted.  I acknowledge that the
attorneys-in-fact, in serving in such capacity at my request, are not assuming,
nor is the Company assuming, any of my responsibilities to comply with Section
16 of the Securities Exchange Act of 1934.

This Power of Attorney shall remain in full force and effect until I am no
longer required to file Forms 3, 4 and 5 with respect to my holdings of and
transactions in Company securities, unless I earlier revoke it in a signed
writing delivered to the attorneys-in-fact. Upon signature of this Power of
Attorney, I hereby revoke all previous powers of attorney granted concerning the
subject matter herein.

IN WITNESS WHEREOF, I have caused this Power of Attorney to be executed as of
this 27th day of May, 2009.

/s/ Dennis van Lingen

Dennis van Lingen
Print Name