They allege the man broke into the network and gained administrative privileges.
Police allege he was planning to upload a program which would have targeted the website and render it inaccessible to the public.
The RCMP said Janvier Doyon-Tremblay is charged with two counts of unauthorized use of computers and one count of mischief in relation to data.
The 28-year-old is scheduled to appear at the Ontario provincial courthouse in Ottawa on Nov. 26.
The police said their investigation found that Doyon-Tremblay was under contract with both the RCMP and the House of Commons at the time the hacking occurred.
They say they took immediate measures to preserve the integrity and security of both organization's networks.
The Mounties said they worked closely with the House of Commons, the Surete du Quebec and the Quebec government's shared services centre during the investigation.
The RCMP's Integrated Technological Crime unit, which covers the national capital region, made the arrest.
"There is definitely an increase in computer crimes and they represent a real threat to Canada’s critical infrastructure," said Sgt. Stephane Turgeon.
"The RCMP takes these threats seriously, as they can have a major impact on our economy and our institutions."
The technological crime unit is detailed to protect critical infrastructure and investigate computer crimes of national and international scope.
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