Mystic Knights of Tir Na Nog is a fantasy-adventure television series set in a fantasy version of ancient Ireland, created by Saban Entertainment. It was loosely based on actual Irish mythology. The name is derived from Tír na nÓg, one of the Otherworlds of Irish mythology. It was Saban's first fantasy series to involve knights, dragons, and wizards. It aired on the Fox Kids Network from September 12, 1998 to May 7, 1999.

A second season entitled Mystic Knights: Battle Thunder was planned, but later cancelled, and its budget put towards Power Rangers Lost Galaxy and the English dub version of Digimon: Digital Monsters.

The resulting series was an attempt in doing an original non-Japanese special-effects series rather than adapting from actual Japanese tokusatsu.