During a town hall event in Edmonton, Alberta, last week, Mr Trudeau interrupted the young woman and urged her to say “peoplekind” instead.
Critics accused the prime minister of “mansplaining”, “virtue-signalling” and making up words.
But his spokesman said Mr Trudeau was “a proud feminist” whose policies reflect “commitments to equality”.
A young woman stood up during last Thursday’s town hall and praised Mr Trudeau for having a gender-balanced cabinet.
The audience member, mentioning her membership of a feminist Korean church, said the country needed an economy filled with women.
She then asked the prime minister about his policy on volunteerism and religious organisations.
The young woman ended her question by saying: “Maternal love is the love that’s going to change the future of mankind.”
Mr Trudeau waved his hand and said: “We like to say peoplekind, not necessarily mankind. It’s more inclusive.”
The young woman said: “Exactly, yes, thank you.”
Members of the crowd cheered and applauded.
“We can all learn from each other,” Mr Trudeau said.
The clip has garnered plenty of online commentary, with conservative commentators overseas picking up on the interaction.
Some argued that the word “peoplekind” does not exist in the English language.
Conservative federal politician Michelle Rempel apologised online to the woman who was interrupted by Mr Trudeau.
Others accused the PM of being condescending or overzealous in his political correctness.
But Mr Trudeau also has his defenders. Some have noted the PM asked for the woman’s time to be respected after her meandering remarks elicited groans from audience members.
The woman also interrupted Mr Trudeau to invite him to bible study.
It is not the first time Mr Trudeau has been criticised for political correctness.
He has previously provoked conservative eye-rolling for self-proclaimed feminism and support for making the lyrics to Canada’s national anthem gender-neutral. (Courtesy BBC)