From 1961 until 1969, the Cornwall Royals were successful members of the Central Junior A Hockey League. After an application to join the OHL was rejected, the franchise became one of the inaugural teams of the Quebec Major Junior Hockey League in 1969. The Cornwall Royals were one of the league's premier teams during its tenure in the QMJHL, winning 3 Memorial Cup titles. For the 1981–82 season, the team transferred into the Ontario Hockey League.
The Royals suffered through many tough seasons and poor attendance after moving to the OHL. The switch in leagues alienated many die-hard fans from across the Quebec border. Seeking better fortunes, the franchise moved to Newmarket, Ontario to play as the Newmarket Royals in 1992. In 1994 the team was bought by the Ciccarelli brothers and moved to Sarnia, Ontario as the Sarnia Sting.
The Cornwall Royals are one of only 7 clubs to win consecutive Memorial Cup championships. They did so in 1980 and 1981. In total, the Royals won 3 Memorial Cups, 3 President's Cups, and 5 division titles while in the QMJHL. The Royals did not win any OHL championships.