HMCS St. Pierre was a River-class frigate that served with the Royal Canadian Navy during the Second World War.

[2] The River-class frigate was designed by William Reed of Smith's Dock Company of South Bank-on-Tees.

[4] The name "frigate" was suggested by Vice-Admiral Percy Nelles of the Royal Canadian Navy and was adopted later that year.

[4] 15 Canadian frigates were initially fitted with a single 4-inch gun forward but with the exception of HMCS Valleyfield, they were all eventually upgraded to the double mount.

[5] For underwater targets, the River-class frigate was equipped with a Hedgehog anti-submarine mortar and depth charge rails aft and four side-mounted throwers.

[4] River-class frigates were the first Royal Canadian Navy warships to carry the 147B Sword horizontal fan echo sonar transmitter in addition to the irregular ASDIC.

[2] At the end of May, St. Pierre returned to Canada to undergo a tropicalization refit in preparation for service in the southern Pacific Ocean.