According to Canadian tax laws, cash prizes awarded to Olympic medalist is taxable.  Olympic cash prizes range from $10,000 to $20,000 per member of the winning team.  Taxes are inevitable, make sure you are not caught off guard – plan accordingly so that you can keep more of it.

http://business.financialpost.com/personal-finance/taxes/why-canadas-olympic-medalists-cant-outrun-the-taxman-yet