Randolph Peter Best (né Scanland; born 24 November 1941) is an English retired musician who was the drummer for the Beatles from 1960 to 1962. He was dismissed shortly before the band achieved worldwide fame and is one of several people referred to as a fifth Beatle.

Best's mother, Mona Best (1924–1988), opened the Casbah Coffee Club in the cellar of the Bests' house in Liverpool. The Beatles (at the time known as the Quarrymen) played some of their first concerts at the club. The Beatles invited Best to join the band on 12 August 1960, on the eve of the group's first Hamburg season of club dates. Ringo Starr eventually replaced Best on 16 August 1962 when the group's manager, Brian Epstein, fired Best at the request of John Lennon, Paul McCartney, and George Harrison following the band's first recording session. Over 30 years later, Best received a significant monetary payout for his work with the Beatles after the release of their 1995 compilation of their early recordings on Anthology 1; Best played the drums on 10 of the album's tracks, including the Decca auditions.

After being a member of several commercially unsuccessful groups, Best left the music industry to pursue a career as a civil servant for 20 years before forming the Pete Best Band.

Best's mother, Mona Best, was born in Delhi, India, the daughter of Thomas (a major from Ireland) and Mary Shaw. Pete Best, her first child, was born on 24 November 1941 in Madras, then part of British India. Best's biological father was marine engineer Donald Peter Scanland, who subsequently died during World War II. Best's mother was training to become a doctor in the service of the Red Cross when she met Johnny Best, who came from a family of sports promoters in Liverpool who ran Liverpool Stadium, a boxing arena. During World War II, Johnny Best was a commissioned officer serving as a Physical Training Instructor in India and was the Army's middleweight boxing champion. Soon after their marriage on 7 March 1944 at St Thomas's Cathedral, Bombay, Rory Best was born. In 1945, the Best family sailed for four weeks to Liverpool on the Georgic, the last troop ship to leave India, carrying single and married soldiers who had previously been a part of General William Slim's forces in south-east Asia. The ship docked in Liverpool on 25 December 1945.

Best's family lived for a short time at the family home, "Ellerslie" in West Derby until Best's mother fell out with her sister-in-law, Edna, who resented her brother's choice of wife. The family then moved to a small flat on Cases Street, Liverpool, but Mona Best was always looking for a large house—as she had been used to in India—instead of one of the smaller semi-detached houses prevalent in the area. The Bests moved to 17 Queenscourt Road in 1948 and remained there for nine years.

Best passed the eleven plus exam at Blackmoor Park primary school in West Derby and was studying at the Liverpool Collegiate Grammar School in Shaw Street when he decided he wanted to be in a music group. Mona bought him a drum kit from Blackler's music store, and Best formed his own band, the Black Jacks.

In 1957, Rory Best saw a large Victorian house for sale at 8 Hayman's Green and told Mona about it. The Best family claim that Mona had pawned all her jewellery to place a bet on Never Say Die, a horse that was ridden by Lester Piggott in the 1954 Epsom Derby; it won at 33–1, and she saved her winnings and in 1957 used them to buy the house. The house, built around 1860, had previously been owned by the West Derby Conservative Club and was unlike many other family houses in Liverpool as it was set back from the road and had 15 bedrooms and an acre of land. All the rooms were painted dark green or brown, and the large garden was totally overgrown. Mona later opened The Casbah Coffee Club in the house's large cellar. The idea for the club first came from Best, as he asked his mother for somewhere his friends could meet and listen to the popular music of the day. As The Quarrymen, John Lennon, Paul McCartney, George Harrison, and Ken Brown played at the club after helping Mona to finish painting the walls. Chas Newby and Bill Barlow joined the Black Jacks, as did Ken Brown, but only after he had left the Quarrymen. The Black Jacks later became the resident group at the Casbah, after the Quarrymen cancelled their residency because of an argument about money.

In 1960, Neil Aspinall became good friends with the young Best and rented a room in the Bests' house. During one of the extended business trips of Best's stepfather, Aspinall became romantically involved with Mona and in 1962, a son, Vincent Roag Best, was born to Aspinall and Mona. Aspinall later became the Beatles' road manager and denied the story for years before publicly admitting that Roag was indeed his son.