Jarrett grew up in suburban Allentown, Pennsylvania with significant early exposure to music. He possessed absolute pitch, and he displayed prodigious musical talents as a young child. He began piano lessons just before his third birthday, and at age five he appeared on a TV talent program hosted by the swing bandleader Paul Whiteman. Jarrett gave his first formal piano recital at the age of seven, playing works by composers including Mozart, Bach, Beethoven, and Saint-Saëns, and ending with two of his own compositions. Encouraged especially by his mother, Jarrett took intensive classical piano lessons with a series of teachers, including Eleanor Sokoloff of the Curtis Institute.
In his teens, as a student at Emmaus High School in Emmaus, Pennsylvania, Jarrett learned jazz and quickly became proficient in it. In his early teens, he developed a strong interest in the contemporary jazz scene; a Dave Brubeck performance was an early inspiration. At one point, he had an offer to study classical composition in Paris with the famed teacher Nadia Boulanger – an opportunity that pleased Jarrett's mother but that Jarrett, already leaning toward jazz, decided to turn down.
Following his graduation from Emmaus High School in 1963, Jarrett moved from Allentown to Boston, Massachusetts, where he attended the Berklee College of Music and played cocktail piano in local clubs. After a year he moved to New York City, where he played at the Village Vanguard.
In New York, Art Blakey hired Jarrett to play with the Jazz Messengers. During a show with that group he was noticed by Jack DeJohnette who (as he recalled years later) immediately realized the talent and the unstoppable flow of ideas of the unknown pianist. DeJohnette talked to Jarrett and soon recommended him to his own band leader, Charles Lloyd. The Charles Lloyd Quartet had formed not long before and were exploring open, improvised forms while building supple grooves. Their 1966 album Forest Flower was one of the most successful jazz recordings of the mid-1960s and when they were invited to play the Fillmore in San Francisco, they won over the local hippie audience. Although the band would become plagued by internal instability and (according to Jarrett) siphoning-off of show revenue by Lloyd, its tours across America and Europe, even to Moscow, made Jarrett a widely noticed musician in rock and jazz underground circles. It also laid the foundations of a lasting musical bond with drummer Jack DeJohnette (who also plays the piano). The two would cooperate in many contexts during their later careers.
In those years, Jarrett also began to record his own tracks as a leader of small informal groups, at first in a trio with Charlie Haden and Paul Motian. Jarrett's first album as a leader, Life Between the Exit Signs (1967), was released on the Vortex label, to be followed by Restoration Ruin (1968), which is arguably the most bizarre entry in the Jarrett catalog. Not only does Jarrett barely touch the piano in the latter album, but he plays all the other instruments on what is essentially a folk-rock album, and even sings. Another trio album with Haden and Motian, titled Somewhere Before, followed later in 1968, this one recorded live for Atlantic Records.