He became interested in folk music and rock & roll in his teens while attending Hammersmith College and in 1965 began performing under the name Steve Adams. Mike Hurst, a former member of the folk-pop group the Springfields, who had become a record producer, heard him and took him into a recording studio to cut his composition "I Love My Dog." This demo caused Decca Records to sign him under the name Cat Stevens and assign him to its newly formed Deram subsidiary. "I Love My Dog" reached the British charts in October 1966, peaking in the Top 40. Stevens' next single, "Matthew & Son," entered the charts in January 1967 and just missed getting to number one (in America, it grazed the bottom of the charts). It was another self-written effort, and Stevens' reputation as a writer was further enhanced by the success of his song "Here Comes My Baby," which was recorded by the Tremeloes and entered the British charts in February, reaching the Top Five. (In America, it peaked just outside the Top Ten.)

Stevens' third single, "I'm Gonna Get Me a Gun," entered the British charts in March and reached the Top Ten, preceded by his debut album, Matthew & Son, also a Top Ten entry. In May, P.P. Arnold got into the British charts with Stevens' composition "The First Cut Is the Deepest," peaking in the Top 20. (Ten years later, Rod Stewart topped the U.K. charts and reached the U.S. Top 20 with his revival of the song. Sheryl Crow revived it for an American Top 20 hit in 2003.) Stevens' fourth single, "A Bad Night," was in the charts in August, peaking in the Top 20. That was a disappointment, considering his recent success, and his next records did even worse: "Kitty," his fifth single, barely made the charts in December, while New Masters, his second album, didn't chart at all. Even worse, in March 1968, Stevens contracted tuberculosis and was hospitalized for three months. He spent a year recuperating. After the failure of an intended comeback single, "Where Are You," released in July 1969, he parted ways with Deram.

Disillusioned by his experience in the music business, Stevens began writing more personal, introspective material. He signed a new contract with Island Records and released his third album, Mona Bone Jakon, in April 1970. Drawn from the album, the single "Lady D'Arbanville" was issued in June 1970 and became his third Top Ten hit in the U.K., causing Mona Bone Jakon to chart modestly in July. Stevens' talent as a songwriter for others had not deserted him; in August, Jimmy Cliff entered the British charts with his composition "Wild World," reaching the Top Ten. With a backlog of material, Stevens had a second Island album, Tea for the Tillerman, out in November; it made the U.K. Top 20. In America, where his Island recordings were licensed to A&M Records, Mona Bone Jakon had not charted, but Tea for the Tillerman marked his American LP chart debut in February 1971, followed shortly by the single release of his own recording of "Wild World," which appeared on the album; it peaked in the Top 20. With that, Stevens suddenly became a major star in the U.S. Tea for the Tillerman reached the Top Ten and went gold; Mona Bone Jakon finally reached the charts (it was belatedly certified gold in 1976); and Deram reissued Matthew & Son and New Masters as a two-LP set, which also charted. Stevens was hailed as one of the most important figures in the currently popular folk-rock singer/songwriter trend, along with James Taylor, Carole King, and others.

In June 1971, Stevens released a new single, "Moon Shadow," which made the Top 40 in the U.S. and the U.K. This was followed in September by "Peace Train," which hit the pop Top Five and reached number one in the easy listening charts in the U.S., just in advance of Stevens' fifth album, Teaser and the Firecat. An immediate gold-record seller, the LP just missed the top of the U.S. charts and hit the Top Five in the U.K. In addition to "Moon Shadow" and "Peace Train," it contained "Morning Has Broken," an adaptation of a hymn, which became Stevens' second consecutive easy listening number one and reached the pop Top Ten on both sides of the Atlantic. Meanwhile, Deram compiled another collection of juvenilia, Very Young and Early Songs, which peaked in the U.S. Top 100 in early 1972, as did a belated American release of the single "Where Are You."

Stevens contributed new and old songs to the film Harold and Maude, a black comedy that became a cult success after its release in 1972, though no soundtrack album was released. (The previously unreleased songs from the film finally turned up on his album Footsteps in the Dark: Greatest Hits, Vol. 2 in 1984.) He also toured and worked on his sixth album, Catch Bull at Four. A slightly harder-rocking effort, the LP, released in October 1972, represented Stevens' commercial peak: it hit number one in the U.S. and just missed duplicating that feat in the U.K., earning gold-record status immediately. Different singles from the album were released in the two countries, in the U.S. "Sitting" and in the U.K. "Can't Keep It In"; both reached the Top 20.

By 1973, Stevens was again beginning to show signs of the strain of being a pop star, even if he didn't become physically ill. For tax reasons, he left the U.K. for a year and moved to Brazil, but he donated the money he would have paid in taxes to charity. He performed less often and stopped granting interviews. In June, he released a new single, "The Hurt," which made the U.S. Top 40. It was followed in August by his seventh album, Foreigner, an ambitious effort that featured an entire LP side given over to a musical suite. The record was another massive commercial success, peaking inside the Top Five in the U.S. and U.K. and going gold instantly. His major appearance for the year was a 90-minute performance on the American TV show In Concert in November.

Stevens issued his eighth album, Buddha and the Chocolate Box, in March 1974, preceded by the single "Oh Very Young," a Top Ten hit. As usual, the album made the U.S. and U.K. Top Five and went gold upon release. In July, Stevens released an independent summer single, a revival of Sam Cooke's "Another Saturday Night," and it made the U.S. Top Ten and the U.K. Top 20. In November, A&M extracted "Ready" from Buddha and the Chocolate Box and released it as a single that made the Top 40. Stevens' Greatest Hits LP was released in June 1975 and predictably was a big success, eventually selling over three million copies in the U.S. alone. "Two Fine People," a new song featured on it, reached the American Top 40. Stevens had his ninth regular album release, Numbers, ready by November. As if in acknowledgment that his greatest hits were now behind him, the album only made the Top 20 in the U.S., though it was certified gold within a couple of months, did not generate a Top 40 single, and missed the charts entirely in the U.K. Stevens took 18 months to deliver his tenth album, Izitso, in May 1977. It restored some of his commercial clout, hitting the U.S. Top Ten and being certified gold in a month, while reaching the U.K. Top 20, and the single "(Remember the Days of The) Old School Yard" made the Top 40 in America and charted in Great Britain.

On December 23, 1977, Stevens formally became a Muslim and adopted the name Yusuf Islam. Notwithstanding this change, there was an 11th and final Cat Stevens album, Back to Earth, released in December 1978; it sold modestly. With that, Yusuf Islam announced his retirement from the pop music business. He entered into an arranged marriage that eventually produced five children, auctioned off his possessions, and founded a Muslim school near London. He was not widely heard from for another ten years, until he made news at the end of the '80s by commenting on the Ayatollah Khomeini's fatwa against novelist Salman Rushdie for writing the book The Satanic Verses. Islam later explained he was not calling for Rushdie's death but that he was defining Islamic law in the same way a Bible student would "quote the legal punishment of a person who commits blasphemy in the Bible." Still, "classic rock" radio stations discontinued playing him as a result, and 10,000 Maniacs, who had covered "Peace Train" on their In My Tribe album in 1987, had it removed from the record.

In 1990, the compilation album The Very Best of Cat Stevens reached the U.K. Top Five. A different album with the same title charted in the U.S. in the spring of 2000, as Yusuf Islam undertook a promotional tour in connection with the reissues of remastered versions of his Cat Stevens albums. Then, in 2006, nearly 30 years after the final Cat Stevens studio album, he released a new studio effort, An Other Cup, under the name Yusuf. In early 2009 he collaborated with "fifth Beatle" Klaus Voormann for a cover version of George Harrison's "The Day the World Gets 'Round." All proceeds from the song were donated to a charity to help the children of war-torn Gaza. Later that same year he released the album Roadsinger. Yusuf toured often during the years after its release, and in 2010 he appeared at "The Rally to Restore Sanity and/or Fear," an event hosted in Washington, D.C. by American satirists Jon Stewart and Stephen Colbert; Yusuf sang "Peace Train" as a counterpoint to Ozzy Osbourne's "Crazy Train," while both were topped by the O'Jays' performance of "Love Train." The year 2012 saw the premiere of Moonshadow, a stage musical built around Cat Stevens' best-known songs, which opened in Melbourne, Australia. In April 2014, he was inducted into the Rock and Roll Hall of Fame. In October of that same year, a third album under the Yusuf name appeared, entitled Tell 'Em I'm Gone. The album, produced by Rick Rubin and featuring guitar work from Richard Thompson, saw Yusuf returning to the early blues and R&B that had inspired him as a young man. ~ William Ruhlmann