Roland Pembroke Hanna was born in Detroit on February 10, 1932, and started formal classical piano lessons at eleven. His first music teaching came from his father, a saxophone player and minister. Jazz reached him sideways, through a school friend named Tommy Flanagan, and by his years at Cass Technical High School he was already working around the city alongside Flanagan, Barry Harris, and Hank Jones. Critics later grouped the four of them as a Detroit school of piano playing, built on dense harmony, bebop fluency, and a deliberately unhurried touch, though Hanna himself never accepted that there was any such single style. Two years in a United States Army band (1950 to 1952) interrupted the apprenticeship. He enrolled at the Eastman School of Music in 1953 and left after a year, frustrated by its restrictions on playing jazz, married Ramona Woodard in 1954, and moved to New York in 1955 to enter the Juilliard School, graduating in 1960.

He worked steadily while he was still a student. In 1958 he toured Europe with Benny Goodman's orchestra, including the band's residency at the Brussels World's Fair documented on Benny in Brussels, and appeared at that summer's Newport Jazz Festival; he was also a regular on the television program Art Ford's Jazz Party alongside Coleman Hawkins, whose quartet he would later join in Flanagan's old chair. Charles Mingus used him intermittently across the same stretch, putting him at the piano for the November 1, 1959 Mingus Dynasty session for Columbia and again for Pre-Bird in May 1960. On August 25, 1959 he played the second set of Kenny Burrell's On View at the Five Spot Cafe for Blue Note. His own leader career began in the same window: ATCO recorded him on April 16 and 17, 1959 playing Harold Rome's score to Destry Rides Again, with Burrell on guitar, George Duvivier on bass, and Roy Burns on drums, then again for the trio date Easy to Love. After Juilliard he spent time accompanying singers, Sarah Vaughan and Al Hibbler among them, and from 1963 to 1966 he led his own trio in New York clubs including the Five Spot.

The association that defined his reputation began in 1966, when he took the piano chair in the Thad Jones/Mel Lewis Orchestra. He was not there at the start: Hank Jones played the band's opening Monday nights at the Village Vanguard and the May 1966 studio debut Presenting Thad Jones/Mel Lewis and the Jazz Orchestra, and Hanna's first record with the group is the Presenting Joe Williams date cut at A&R Studios that September. From there he held the chair for eight years and played on nearly everything the band issued: Live at the Village Vanguard (April 28, 1967), Monday Night (October 17, 1968), Central Park North (1969), Consummation (1970), Live in Tokyo and Potpourri (both 1974), and, from sessions he had already played, Suite for Pops and New Life. He toured the Soviet Union with the orchestra in 1972 and Japan in 1974, sharing the rhythm section over those years with Richard Davis and then George Mraz, and the reed section with Pepper Adams on baritone. He left in June 1974, put off by the band's drift toward electric instruments and rock rhythms, and said later that he had softened on the point: he still would not play electric keyboards, but he could listen to them.

The band's most-recorded piece came out of his hands. Over several weeks at the Vanguard in 1969, Hanna improvised a tune between sets that the band began playing off; Thad Jones wrote it down, arranged it, and brought it in as "A Child Is Born." When Hanna asked whether it was his tune, Jones told him it was not. Hanna's own account, given to Monk Rowe in a 2000 interview now held at Hamilton College, is that he bore no grudge and considered the tune gifted to Jones, since writing material down was what bandleaders did. Alec Wilder heard the orchestra play it, went back to the Algonquin Hotel, and wrote a lyric. The first recording is on Consummation, and the song has since become a standard.

In 1970 the government of Liberia gave Hanna an honorary knighthood. It was a real one, conferred by President William V. S. Tubman in recognition of a run of solo concerts Hanna had played in the country that raised money for children's education. From that point he was billed on many of his records as Sir Roland Hanna, and Discogs carries "Sir Roland Hanna" and "Sir Roland P. Hanna" among his registered name variations. His own catalog expanded fast in the decade that followed. Child of Gemini (MPS, 1971) put him in a trio with Dave Holland and Daniel Humair; Sir Elf (Choice, 1973) was the first of many solo records; Perugia captured a solo set at the Montreux Jazz Festival on July 2, 1974. He founded the New York Jazz Quartet, initially with Hubert Laws, Ron Carter, and Billy Cobham, and reorganized it in 1974 around Frank Wess, with Carter and then Mraz on bass and Ben Riley, Richard Pratt, and Grady Tate rotating on drums; it recorded through 1982 for Salvation, Sonet, Enja, and Bee Hive. A parallel run of duo records with Mraz produced 1 X 1 (1974), Porgy & Bess (1976), Play for Monk (1978), and Romanesque (1982). Japanese labels became his most reliable outlet: Trio, Salvation, Progressive, and Lob between them issued a dozen of his albums, among them the two-volume 24 Preludes, an original cycle in all twenty-four keys that he recorded in Tokyo in June 1976 and October 1977.

Hanna was in semi-retirement for most of the 1980s, though he wrote and played "Seasons" for Sarah Vaughan's 1982 Pablo album Crazy and Mixed Up, and he came back in the second half of the decade with solo records for Town Crier and Fun House. In the late 1980s and early 1990s he held chairs in both the Lincoln Center Jazz Orchestra and the Smithsonian Jazz Masterworks Orchestra, and he taught as a tenured professor of jazz at the Aaron Copland School of Music at Queens College, CUNY. He kept writing across idioms, including a ballet score for BalletMet Columbus and a sonata for piano and violin commissioned by the Library of Congress; published counts of his output range from more than 200 pieces to more than 400. His last studio dates came in the two years before his death, for IPO in Purchase, New York and for the Japanese label Venus in Manhattan. Roland Hanna passed away in Hackensack, New Jersey, on November 13, 2002, at seventy, from a viral infection of the heart. Two of his final sessions, Tributaries: Reflections on Tommy Flanagan and Après un Rêve, were released the following year.

Hanna's conservatory training was not decoration. He had a bravura technique that took him into territory most jazz pianists avoid, and he used it to fold Chopin-scale keyboard writing, French impressionist harmony, and nineteenth-century romantic figuration into a bebop vocabulary he had learned in Detroit next to Tommy Flanagan, Barry Harris, and Hank Jones. Critic Len Lyons grouped the four of them for their tasteful accompaniment and their sophisticated handling of modern harmony in trio work. What set Hanna apart within that group was his appetite for genuinely open-ended improvising: pianist Dick Katz, writing the notes for Tributaries, said Hanna "never played a piece the same way twice." That came at a cost in visibility. He was an unmistakable presence inside other people's bands, most of all as the harmonic anchor under Thad Jones's brass writing, and his own records sold modestly and were often available only as Japanese imports. He was also a working composer with a catalog outside jazz entirely, and his 24 Preludes cycle, a set of original pieces in all twenty-four keys with dedications to Coleman Hawkins and to individual cities, is the clearest statement of what the two halves of his training could do together.