Lewis Brian Hopkin Jones (28 February 1942 – 3 July 1969) was an English musician and one of the founders of the Rolling Stones. Initially a slide guitarist, he went on to play electric guitar, sing backing vocals and play a wide variety of instruments on Rolling Stones recordings and in concerts.

After he founded the Rolling Stones as a British blues outfit in 1962 and gave the band its name, Jones's fellow band members Keith Richards and Mick Jagger began to take over the band's musical direction, especially after they became a successful songwriting team.

When Jones developed alcohol and drug problems, his performance in the studio became increasingly unreliable, leading to a diminished role within the band he had founded. In June 1969, the Rolling Stones dismissed Jones; guitarist Mick Taylor took his place in the group. Less than a month later, Jones died by drowning at the age of 27 in the swimming pool at his home at Cotchford Farm, East Sussex. His death was referenced in songs by many other pop bands, and Pete Townshend and Jim Morrison wrote poems about it. In 1989, he was inducted into the Rock and Roll Hall of Fame as a member of the Rolling Stones.

Lewis Brian Hopkin Jones was born in the Park Nursing Home in Cheltenham, Gloucestershire, on Saturday, 28 February 1942. An attack of croup at the age of four left Jones with asthma that lasted for the rest of his life. His middle-class parents, Lewis Blount Jones and Louisa Beatrice Jones (née Simmonds), were of Welsh descent. Brian had two sisters: Pamela, who was born on 3 October 1943 and died on 14 October 1945 of leukaemia; and Barbara, who was born on 22 August 1946.

Jones attended local schools, including Dean Close School from September 1949 to July 1953; and Cheltenham Grammar School for Boys, (now Pate's Grammar School) which he entered in September 1953 after passing the eleven-plus exam. He enjoyed badminton and diving at school and became first clarinet in the school orchestra. Jones reportedly obtained seven O-level passes in 1957, thence continuing into the sixth form and obtaining a further two O-levels. He passed A-levels in physics and chemistry, but he failed in biology.

Jones was able to perform well in exams despite a lack of academic effort. However, he found school regimented and disliked school uniforms and conformism in general; Jones himself said: "When I made the sixth form, I found myself accepted by the older boys; suddenly I was in." His hostility to authority figures resulted in his suspension from school on two occasions. According to Dick Hattrell, a childhood friend, "He was a rebel without a cause, but when examinations came he was brilliant."

Both Jones's parents were interested in music; his father was a piano teacher in addition to his job as an aeronautical engineer, and his mother played the piano and organ and led the choir at the local church. Jones listened to classical music as a child but preferred blues, particularly Elmore James and Robert Johnson. In 1957, he first heard Cannonball Adderley's music and took an interest in jazz. Jones persuaded his parents to buy him a saxophone, and two years later, his parents gave him his first acoustic guitar as a 17th birthday present. Jones began performing at local blues and jazz clubs while busking and working odd jobs. He reportedly stole small amounts of money from work to pay for cigarettes, for which he was sacked.

Jones's first child was born in 1958 to a female friend. The baby, of unknown sex, was given up for adoption and, in contrast to Jones's other children, has either not learned of the relationship to Jones, or has not publicly identified themselves as Jones's child.