Sinjin Knightfire is a minor character featured in the Disney XD series Randy Cunningham: 9th Grade Ninja. This magician is the owner of the Knightfire Magic Funporium. He was the entertainer for Julian's party in "Julian's Birthday Surprise". He also appears in "McNinja - Brought to You by McFist", wherein he is one of the sponsors to get Stanked by the Sorcerer.
- His first name, "Sinjin," is the British pronunciation of the given name "St. John," so that his entire name can be construed as "St. John's Night fire." In European legend, "St. John's Night" or "St. John's Eve" (June 23, which was formerly also Midsummer Eve, the day before the summer solstice) was a magical night (as in Shakespeare's A Midsummer Night's Dream or Mussorgsky's Ночь на лысой горе), often associated with the kindling of bonfires. Thus Knightfire's name is an elaborate, if obscure, reference to his magical nature.
- Following on this, Sinjin's rather devilish appearance when stanked may be a glancing reference to Disney's own Chernabog in Fantasia.