Châteauguay borough's council voted to dismiss the officer at their monthly meeting this week.
Mayor Natalie Simon said one person had been filing complaints about the officer for months. Simon said an investigation suggested the officer may have breached the code of ethics.
"He misbehaved on many occasions for the last [few] years. So as far as I'm concerned, he didn't have a good police behaviour for years now, so we had to fire him," she said.
The mayor believes the officer may have abused his position of power to gain favours and is also accused of breach of trust and lack of integrity.
Police are also investigating and charges could be laid.