Pierre Blais, who served as justice minister under Brian Mulroney before moving to the bench, will serve as chair of the committee, which is charged with reviewing the activities of the Canadian Security Intelligence Service.
He replaces former Conservative MP Deborah Grey, who took over the job on an interim basis last January following the resignation of Harper's former public safety minister, Chuck Strahl, over controversy related to his lobbying efforts on behalf of Enbridge's Northern Gateway pipeline proposal.
Blais retired from the Federal Court of Appeal last fall after spending six years as chief justice.
SIRC's oversight capacity questioned during hearings
Blais will be joined at the committee table by another new appointee, Marie-Lucie Morin, who served as Harper's national security advisor from 2008-2010.
"Both Mr. Blais and Ms. Morin have had distinguished careers of public service in which they have acquired extensive experience of national security matters," Harper said in a written statement announcing the appointments.
"Their wealth of knowledge and expertise will further strengthen the oversight of the Canadian Security Intelligence Service as it prepares to take on critical new responsibilities to protect Canadians."
The role of SIRC — and, particularly, its ability to provide the robust oversight — has been a focal point of the ongoing debate over the anti-terror bill.
Privacy and civil liberties advocates have questioned whether the committee has the resources or mandate to ensure the rights and privacy of Canadians will be protected under the proposed new law, which would dramatically boost the power of CSIS to investigate potential threats.
During committee study of the bill earlier this spring, former SIRC chair Ron Atkey described a provision that would allow CSIS agents to apply for judicial approval to breach charter rights a "constitutional mess."
The bill is expected to go to a final House vote next week, at which point it will move to the Senate, where the national security committee has already begun its review.