HMS Orion was a Leander-class light cruiser which served with distinction in the Royal Navy during World War II. She received 13 battle honours, a record only exceeded by HMS Warspite and matched by two others.

The Leander class was a class of eight light cruisers built for the Royal Navy in the early 1930s that saw service in World War II. They were named after mythological figures, and all ships were commissioned between 1933 and 1936. The three ships of the second group were sold to the Royal Australian Navy (RAN) before World War II and renamed after Australian cities.