HMS Argus was a British aircraft carrier that served in the Royal Navy during World War I and World War II. It was the first ship to be designed and built as a fully-fledged aircraft carrier, and its launch marked the beginning of a new era in naval aviation. The ship was used for training and experimental purposes during World War I, and served as a convoy escort and transport vessel during World War II. After the war, Argus was decommissioned and eventually scrapped in the mid-1940s.