In the film Fantastic Beasts and Where to Find Them, Theseus Scamander was the brother of Newt Scamander. He is only mentioned in the film, as he was a famous war hero in World War I.
In the Canadian television show Continuum, Theseus is the alias of Liber8 leader Julian Randol. Along with his father, Julian has an anti-corporate agenda, believing that corporations are controlling our governments. Kiera, the protector from the future, has knowledge of horrific crimes committed by Theseus. When she learns of his true identity, she is faced with a Hitler murder paradox. In the end, she lets Julian live, but fears she may have helped create the monster he is to become.
In the Hercules: The Legendary Journeys, Theseus was a boy who was sent by his mentor, Ceridian, secure Hercules aid in stopping another student, Cassius, who was about to begin a war.
EAS Theseus was a Omega-class destroyer in Babylon 5.
The Theseus Morpho is a type of butterfly.
In Greek Mythology, Theseus killed the Minotaur in a labyrinth, using a ball of string given to him by King Minos' daughter to find his way out. In Doctor Who, the Fourth Doctor claimed that he had been the one to give the string to Theseus.
In 2012, 41 boys were given the name Theseus.