Two vessels of the Royal Canadian Navy have been named HMCS Rainbow, after the rainbow.

• HMCS Rainbow (1891), an Apollo-class protected cruiser operated by the Royal Navy from 1893 to 1909 as HMS Rainbow, transferred to Canada in 1910, and operated until 1920
• HMCS Rainbow (SS 75), a Tench-class submarine operated by the United States Navy from 1944 to 1968 as USS Argonaut (SS-475), sold to Canada in 1968, and operated until 1974

See also

• HMS Rainbow, nine ships of the Royal Navy, including the first HMCS Rainbow
• USS Rainbow (AS-7), a distilling ship and submarine tender of the United States Navy

List of ships with the same or similar names

This article includes a list of ships with the same or similar names. If an internal link for a specific ship led you here, you may wish to change the link to point directly to the intended ship article, if one exists.