One of Renfrew's claims to fame is being the birthplace of the National Hockey League (NHL) and home of the Renfrew Millionaires. MJ O’Brien settled here from Montreal after meeting his wife in Calabogie. His vast fortune was made from the lumber industry followed by railways, munitions plants and hockey. He owned four of the six first National Hockey Association (NHA) teams making him the father of, and Renfrew the birthplace of, the NHA/NHL.