Justin Trudeau interrupted a woman during a Q&A session to tell her to use the word "peoplekind" not "mankind".
The audience applauded in agreement as the Canadian prime minister said: "We like to say peoplekind, not necessarily mankind."
He was responding to a woman who said her charitable religious organisation was having difficulty with volunteering regulations in Canada.
Asking Mr Trudeau to look into the matter the woman, speaking at an event at MacEwan university, said: "Maternal love is the love that's going to change the future of mankind."
After the premier corrected her, the woman took it in good humour and said laughingly: "There we go, exactly."
He shot back: "We can all learn from each other."
The remark drew some mockery on social media with Piers Morgan tweeting "FFS" while another man asked: "Is Trudeau mansplaining feminism?"
The 46-year-old politician has spoken about men's role in changing inequalities suffered by women.
He wrote in an essay in Marie Claire in October that “our sons have the power and the responsibility to change our culture of sexism”.
