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

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

[5] 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.

[6] 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.

[5] 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.

She returned to Canada in June 1945 to undergo a tropicalization refit at Dartmouth for possible service in the southern Pacific Ocean.

The Department of Transport had just acquired and altered two other River-class frigates, Stone Town and St. Catharines, to place on station in the Pacific as weather ships.