Billy Morrison (born 9 February 1969) is a British musician who plays guitar with Billy Idol, performs with the Los Angeles-based cover band Royal Machines, and fronts the hard rock act Circus Diablo. He was previously a member of Camp Freddy. He has also toured with The Cult.

Morrison was born in the UK and is an only child. Early in his career, he was a member of the indie rock band Into a Circle. Consistent abuse of drugs led to a period of inactivity until he recovered and formed Stimulator in 1995. The band signed a recording contract with Geffen Records and recorded an album, but the company never released it. In 2008, Morrison released the album under his own name, stating "When I read about Tunecore, and when the business started to lend itself to home releases – the indie, DIY approach – I wanted to finally release it. All the hard copies sold out, and it still does good business on iTunes. I would call that a success."

In 2001, at the request of Billy Duffy, Morrison joined The Cult as the band's bass player. Although he primarily plays rhythm guitar, he enjoyed the idea of playing bass for such a seminal rock band. He toured with The Cult for more than a year, which included playing shows in the UK and Japan and touring with Aerosmith in the U.S.

During a subsequent period of inactivity for The Cult, Morrison joined forces with Pitchshifter frontman J.S. Clayden and formed Doheny. However, no material from Doheny was released commercially. In 2009, Morrison talked about the experience in an interview. "We wrote some songs together, had a laugh and put a lineup together, but I think Doheny suffered from being over-rehearsed and under-funded. We played every note perfectly and had no money to get out on the road and get out of L.A. That was it. But some great songs came out of those years. We should release them."

In 2002, Morrison joined forces with Dave Navarro, Matt Sorum, Donovan Leitch and Scott Ford to form Camp Freddy. In addition to his performances with the band, Morrison hosted a radio show, Camp Freddy Radio, on Los Angeles–based Indie 103.1 for three years with Navarro and Leitch.

Morrison began acting in 2005 and delivered his first on-screen performance in the independent movie Tripping Forward as drug dealer Sweaty Steve. Since then, he has made other independent films, including Evilution, Basement Jack and K-11 (directed by Jules Stewart). He has described the acting process as "something I would love to do more of", and he continues to develop TV and film projects.

In 2006, Morrison formed Circus Diablo with fellow The Cult guitarist Billy Duffy and former Fuel frontman Brett Scallions on bass guitar. The lineup was completed by former The Almighty front man Ricky Warwick and Slunt drummer Charles Ruggiero. The band subsequently added former Korn guitarist Rob Patterson and singer-songwriter Patrick Cornell to its lineup. The band's first album released in July 2007, and the first single, "Loaded", reached number 29 on the Active Rock Chart. For a time, the video for the song was the most viewed music video on YouTube, with more than 1,000,000 hits.

In March 2009, Morrison talked about his plans for the future: