HMCS Prestonian was a River-class frigate that served with the Royal Canadian Navy during the Second World War and as a Prestonian-class frigate from 1953–1956. She saw action primarily as a convoy escort. She was named for Preston, Ontario, however due to possible confusion with HMS Preston, her name was altered. In 1956 she began service with the Royal Norwegian Navy as Troll.Prestonian was ordered on 1 February 1943 as part of the 1943–1944 River-class building program.