Stewart Armstrong Copeland (born July 16, 1952) is an American musician and composer. He is best known as the drummer of the English rock band the Police (1977–86, 2007–08). Before the Police, he played drums with the progressive rock band Curved Air (1975–76).

As a composer, Copeland's work includes the scores of the films Wall Street (1987), Men at Work (1990), Good Burger (1997), and We Are Your Friends (2015); the theme music for television shows The Equalizer, The Amanda Show, and Dead Like Me; and the scores for video games in the Spyro series and Alone in the Dark: The New Nightmare. He has also written pieces for ballet, opera, and orchestra.

According to MusicRadar, Copeland's "distinctive drum sound and uniqueness of style has made him one of the most popular drummers to ever get behind a drumset". He was ranked the 10th-best drummer of all time by Rolling Stone in 2016. He was inducted into the Rock and Roll Hall of Fame as a member of the Police in 2003, the Modern Drummer Hall of Fame in 2005, and the Classic Drummer Hall of Fame in 2013.

Copeland was born in Alexandria, Virginia, on July 16, 1952, the youngest of four children of Scottish archaeologist Lorraine Copeland (née Adie; 1921–2013) and noted jazz musician and American espionage officer Miles Copeland Jr. (1916–1991). His mother was born in Edinburgh, while his father was from Alabama. His father was, according to his own 1989 biography and files released by the CIA in 2008, a key intelligence operative in Britain during the Second World War and a founding member of the Central Intelligence Agency. Stewart's mother was also an espionage veteran, serving in the British Special Operations Executive.

Miles Copeland was assigned CIA duties in the Middle East and the family moved to Cairo a few months after Stewart's birth. When Stewart was five years old the family moved to Beirut, where he attended the American Community School. He started taking drumming lessons at age 12 and was playing drums for school dances within a year. He later moved to England, attending the American School in London and Millfield boarding school in Somerset from 1967 to 1969. He went to college in California, enrolling at Alliant International University and the University of California, Berkeley. His eldest brother, Miles Copeland III (born 1944), founded I.R.S. Records and became the Police's manager. He has also overseen Copeland's interests in other music projects. His other brother, Ian Copeland (1949–2006), was a pioneering booking agent who represented the Police and many others.

Returning to England, Copeland worked as road manager for the progressive rock band Curved Air's 1974 reunion tour, and then as drummer for the band during 1975 and 1976. The band kicked off with a European tour, which started poorly. Band leader Darryl Way, a notorious perfectionist, grew impatient with the struggling of his bandmates, especially novice drummer Copeland. Then, for reasons no one could pinpoint, the musicians suddenly "clicked" with each other and the band caught fire, quickly becoming a popular and acclaimed live act.

Eventually, Way left the band and after months of gradually losing steam, Curved Air broke up so quietly that, by singer Sonja Kristina's recollections, most of the music press wrote off the band's absence as a "sabbatical". Copeland formed the Police and Kristina and Way both pursued solo careers. Kristina and Copeland maintained the close personal relationship they'd formed while bandmates and were married in 1982.

In early 1977, Copeland founded the Police with lead singer-bass guitarist Sting and guitarist Henry Padovani (who was soon replaced by Andy Summers), and they became one of the top bands of the late 1970s and early 1980s. Copeland was the youngest member of the band. The Police's early track list (before their album debut) was largely Copeland compositions, including the band's first single "Fall Out" (Illegal Records, 1977) and the B-side "Nothing Achieving". Though Copeland's songwriting contribution was reduced to a couple of songs per album as Sting started writing more material, he continued to co-arrange all the Police's songs together with his two bandmates. Amongst Copeland's most notable songs are "On Any Other Day" (where he also sang lead vocals), "Does Everyone Stare" (later to be used as the title of his documentary on the band Everyone Stares: The Police Inside Out), "Contact", "Bombs Away", "Darkness" and "Miss Gradenko". Copeland also co-wrote a number of songs with Sting, including "Peanuts", "Landlord", "It's Alright for You" and "Re-Humanize Yourself".