CCGS Louis S. St-Laurent (French: NGCC Louis S. St-Laurent) is a Canadian Coast Guard (CCG) heavy icebreaker. Louis S. St-Laurent's home port is St. John's, Newfoundland and Labrador. It is the largest icebreaker and flagship of the CCG. The ship is named after Louis St. Laurent, who served as the 12th prime minister of Canada from 1948 to 1957.