Prime Minister Stephen Harper calls Tannas a remarkable Canadian.
The businessman, who won a Senate appointment vote in Alberta in 2012, replaces retiring senator Bert Brown.
Harper says Tannas supports Conservative Senate reform proposals, including term limits.
Western Financial Group provides property, liability and life insurance as well as banking and investment services for more than 550,000 customers in Western Canada.
In 2003, Tannas was named Prairies entrepreneur of the year by Ernst and Young.
Harper says he looks forward to working with the new senator.
"His strong business background and deep knowledge of Alberta are sure to benefit the Senate," Harper said.
Tannas, 51, is from High River, Alta.; his father was a member of the provincial legislature and a former deputy speaker.
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