Happy Birthday, Mr. Christian is the first track on Apollonia 6's first and only album Apollonia 6. Happy Birthday, Mr. Christian was written by Prince, but credited to Apollonia (words) and The Revolution (music).
Basic tracking took place on 2 August 1984 (estimate), at the Flying Cloud Drive Warehouse in Eden Prairie, Minnesota, as the last song recorded for the album. The track replaced Manic Monday on the album (Manic Monday had been included on a Warner Bros. pre-release cassette of the album). The track is the last-known track to be recorded before the release of Prince and the Revolution's album Purple Rain.
The song contains a segment of the traditional song Happy Birthday To You.