Filmon is a social worker, motivational speaker and volunteer known for her charitable work.
She is the chairwoman of the CancerCare Manitoba Foundation and has a cancer leadership award named after her.
Filmon was awarded the Order of Canada in 2013 and named an officer of the Order of Manitoba in 2007.
She is also the wife of Manitoba's former Progressive Conservative premier, Gary Filmon.
She succeeds Philip Lee, who has filled the role since 2009.
"Janice Filmon is a strong leader who has been extensively involved in her community for decades. As a champion of health care and education, she has been an exemplary volunteer who has helped a wide range of Manitobans through her tireless efforts," Prime Minister Stephen Harper said in a release Monday.
Lieutenant-governors are the representatives of the Queen in each province and grant royal assent to laws.
They are appointed by the Governor General of Canada on the recommendation of the prime minister and serve terms of no less than five years.