Boissonnault represents Edmonton Centre and is the first out-gay MP elected in Alberta. His new role is the first of its kind in federal politics.
The appointment from Justin Trudeau's office comes along with an announcement the government has introduced legislation to repeal Canada's anal sex laws.
Under section 159 of the Criminal Code, anal sex is only legal if it takes place between a husband and wife, or two consenting adults over the age of 18. It's also illegal if more than two people "take part or are present." The age of consent for other types of sex is 16.
Although homosexuality was decriminalized in Canada in the 1960s, the restrictions in section 159 have remained and long been called discriminatory.
"The offence disproportionately impacts on gay males, particularly 16- and 17-year-olds, who can lawfully consent to all other forms of non-exploitive sexual activity," said a statement from the government.