Billy Sherwood's music career started with Lodgic, formed with big brother Michael Sherwood, also including Guy Allison on keyboards, Jimmy Haun on guitar and Gary Starns on drums. They eventually moved the band to Los Angeles in 1980. Lodgic eventually broke up, and Billy Sherwood put together a new band with Guy Allison. They recruited guitarist Bruce Gowdy and drummer Mark T. Williams to form World Trade. They recorded their self-titled debut in 1989, with Sherwood taking on the roles of engineer, mixer, and producer again, along with his band duties as bassist and lead singer.
Then, Sherwood and Gowdy were asked to come and jam with Chris Squire, Alan White, and Tony Kaye of Yes. Singer Jon Anderson and guitarist Trevor Rabin had left the band and the idea was for Sherwood and Gowdy to replace them in the band. Rabin returned to the band, but demos were recorded by a line-up of Squire, White, Kaye, Rabin and Sherwood. However, Yes were to merge with Anderson Bruford Wakeman Howe and Sherwood was relegated to a side musician, appearing on one track of the subsequent album Union. Like Trevor Horn before him, Sherwood was uncomfortable with the idea of replacing Anderson as the front man of Yes, but he struck up a friendship with Squire that would lead to work with him throughout the next 20 years.
During the hiatus of Yes, Squire put together the Chris Squire Experiment, having Sherwood as the lead singer while playing some guitar and keyboards. Sherwood then went on to record a project called The Key with guitarist Marty Walsh, though they would not release the album until 1997.
Behind the board, Sherwood worked with Mot?rhead, Dangerous Toys, and Paul Rodgers (formerly of Bad Company) as producer and engineer. Sherwood also guested on Toto's Kingdom of Desire album, singing and playing bass. He also produced a couple of tribute albums, including Jeffology, a tribute to Jeff Beck. Sherwood then joined Yes on tour as an additional musician, playing guitar and keyboards for their tour in support of Talk.
Sherwood got back together with his band mates from World Trade and released Euphoria in 1995, with Jay Schellen replacing Williams on drums. After this, he worked with a multitude of artists. Most of his work was as producer, mixer and engineer, including on more tribute albums: Dragon Attack, a tribute to Queen; Salute to AC/DC; and Crossfire, a tribute to Stevie Ray Vaughan.
Sherwood would co-produce, engineer and mix the new studio tracks for Yes's Keys to Ascension and Keys to Ascension 2 albums. Sherwood started work on a third album by World Trade, but the band would fall apart. He would later use much of that material as his debut solo album The Big Peace, released in 1999.
After the two Keys to Ascension albums, Rick Wakeman left Yes. Sherwood's friendship with Chris Squire would then lead him being asked to join the band again. The material that they had written together was used as the basis of what would become Open Your Eyes, released in 1997 by Yes. Sherwood played guitar and keyboards. Igor Khoroshev would join the band before the tour as the keyboardist leaving Sherwood to playing guitar and supplying backing vocals.
After returning from the tour, Sherwood and Yes returned to the studio to record The Ladder. During this time too, Sherwood and Squire started putting the finishing touches on their album Conspiracy, largely based on the Chris Squire Experiment material, which was released while Yes was on tour in support of The Ladder in 2000. Billy also took time to perform on his brother Michael's album Tangletown, released in 1999.
In 2003, Sherwood released another album with Chris Squire, the project becoming known as Conspiracy. The album was titled The Unknown.
More recently, Sherwood has been working on further tribute albums, notably Back Against The Wall and Return To The Dark Side Of The Moon, tributes to Pink Floyd's The Wall and Dark Side of the Moon respectively. The latter includes a new track recorded with Tony Kaye.
In 2007, a new band with Sherwood, Alan White, Tony Kaye and Jimmy Haun was announced, called Circa:.