Wallin's office confirmed Tuesday that the senator, who turns 60 April 10, is taking a leave of absence as chair of the Senate defence committee.
She's also stepping away from two other committees she sits on.
There was no elaboration on the nature of the personal reasons and it was not known when she might rejoin the committees.
In recent months Wallin has come under scrutiny for her travel expenses and housing allowance, though she has defended them as acceptable.
Wallin, a former broadcaster, has battled colorectal cancer.
In January, she was interviewed by Catherine Clark for the CPAC program Beyond Politics and spoke at length about her career in broadcasting and life in the public spotlight.