Yes, you can deduct the commissions paid to the real estate agent.
Your employment expenses include any GST and provincial sales tax (PST), or HST, you paid on these expenses. You may be able to get a rebate of the GST/HST you paid. For more information, seeGST/HST Rebate.
RyleReed, I have been researching on the same topic and I can't find anywhere else says I can claim realtor commission on tax return. I usually file T2125 - statement of business for the hotel rental business. Can you advise where to enter this claim and if there are official link from CRA I can read up on?