Rupert Giles is a character from the Buffy the Vampire Slayer television series played by actor Anthony Stewart Head. He is a British Watcher given the responsibility of teaching and training Buffy Summers in her role as Slayer. In his early years with Buffy he also worked as the librarian at Sunnydale High School. However, with the destruction of the school, he switched focus somewhat and opened a magic shop in the town. Over time, and with Buffy becoming older and wiser, he found his services as a Watcher required less and less, and eventually decided to return to his native England, moving to a place in Bath.

Being a Watcher for Giles is continuing a family profession; his father was a watcher as well as his grandmother. It was believed that being a watcher is a calling as much as being a slayer is.

Young Rupert Giles didn't like the idea of calling, he left university for a while to rebel. Met up with a crowd that includes Ethan Rayne, Philip Henry, Dierdre Page, and started his involvement with black magics, and demon summoning. It was then that he got his nickname, "Ripper".

Rupert went back to answer his calling as a watcher out of guilt and/or a sense of awakening, when one of their friends was killed as a result of summoning Eyghon, a demon that possesses the dead or the unconscious. Ripper's group summoned the demon, because the Eyghon demon gives the host it possesses a sense of ecstasy.

When Eyghon returned decades later, all of Ripper's former group who got the tattoo/mark of Eyghon were killed, with the exception of Giles and Ethan Rayne.

There is talk about a spinoff series from Buffy the Vampire Slayer called Ripper.