Born September 20, 1954, to an English father and a French mother in Luton, a town north of London, England, White and his family moved soon after his birth to nearby Letchworth. His brother Danny was born a few years later. As a child, White loved sports, hiking, and tree climbing, but music was most special to him. His father encouraged him to learn many musical instruments -- recorder, clarinet, cornet, trombone, violin, harmonica, piano -- but the one instrument his dad couldn't help him with was the guitar; White was on his own. He learned to play simple chords by experimenting and listening with one ear glued to the radio. Like a lot of musicians, White was heavily influenced by the Beatles and the guitar-driven sound of the beat groups of the '60s. Around age 12, White would go over to schoolmate David Visick's house and listen to his large record collection. His favorites were Jethro Tull, Led Zeppelin, Fleetwood Mac, Cream, and Jimi Hendrix. He bought his very first LP from Visick, the Beatles' Sgt. Pepper's Lonely Hearts Club Band.

In his early teens, he acquired his first electric guitar and amplifier, which survived just long enough to be burned in a fire. Forced to go acoustic, White developed a love of acoustic music. After leaving school at 18, White worked for a few months in a soup-canning factory before getting his first musical break, a summer engagement at a South of England holiday resort. When summer ended, he went back to Letchworth, having whet his appetite for more musical adventures. Traveling to London, the guitarist ended up joining a group that was managed by Miles Copeland (Sting, R.E.M., IRS Records). Copeland also managed Al Stewart, so when Stewart's backup band disbanded, White got an audition call to back Stewart on keyboards. Brushing up on his finger dexterity, White learned a few of Stewart's songs, and soon the 20-year-old musician was touring England and the U.S. In the summer of 1975, Stewart asked White to play keyboards and acoustic guitar on his Year of the Cat album (Arista, 1976). Their collaboration lasted almost 20 years, with White co-writing "Time Passages" (number seven pop, number one adult contemporary, fall 1978) and co-producing Famous Last Words (Mesa/Rhino, 1993).

Around 1979, White moved to Los Angeles, where Stewart had relocated, formed a band called Shot in the Dark with other musicians who had played with Stewart, and established a music publishing company called Lobster Music. Meanwhile his brother Danny formed the group Matt Bianco, which included a tantalizing singer named Basia Trzetrzelewska. Danny White and Basia left the group to launch the singer's solo career. Basia's 1987 Epic debut album, Time and Tide, went platinum, bolstered by the hit singles "New Day for You" and "Time and Tide." Her second LP, London Warsaw New York (Epic, 1990), mimicked the success of her debut. Danny asked Peter to tour with him and Basia in 1990, just as the guitarist released his first solo album, Reveillez-Vous (Chase). Made up mostly of unused songs that White had written for Al Stewart, the album became a DJ favorite at jazz and emerging smooth jazz radio stations. Epic exec Cliff Gorov was the man who first brought White's music to the attention of contemporary jazz radio. Former Al Stewart drummer Steve Chapman put down his sticks and became the guitarist's manager. After recording three albums for Sin-Drome, White signed with Columbia/Sony in 1995.

White can also be heard on the concert CD Basia on Broadway and on releases by Richard Elliot, Warren Hill, Craig Chaquico, Rick Braun, Marc Antoine, Kirk Whalum, and Everette Harp. White and the aforementioned musicians periodically do a concert tour, An Evening of Guitars, Saxes and More, with each artist showcasing their own music as well as collaborating with others on their songs. His solo work continued throughout the '90s with White releasing a slew of records: Caravan of Dreams (1996), Songs of the Season (1997), and Perfect Moment (1998). By Candlelight: Collection, Vol. 2 was issued two years later. In 2001 Glow came out, followed by Confidential in 2004. White then decided to revisit some of his favorite songs from the '60s, '70s, and '80s in his 2006 release Playin' Favourites. The low-key Good Day followed in 2009. In 2012, White delivered the studio album Here We Go featuring guest appearances by such artists as David Sanborn, Andrew Neu, and Kirk Whalum.