HMS Porpoise was an Acasta-class destroyer of the Royal Navy, which was built by Thornycroft between 1912 and 1914. Porpoise served through the First World War, taking part at the Battle of Jutland in 1916, where she was damaged. In 1920, she was sold to the Brazilian Navy serving under the name Alexandrino de Alencar and was renamed Maranhão in 1927. Maranhão remained in service when Brazil entered the Second World War, being used for patrol and convoy duties. She was disposed of in 1945.