Peter Cincotti was born in New York City on July 11, 1983. His father's family comes from Cervinara, a town in the province of Avellino in southern Italy, and his mother is Jewish. His grandmother gave him a toy piano when he was three, and by his own account he could pick out the chords to "Happy Birthday" by ear. Lessons began a year later, and he went on to study classical piano at the Manhattan School of Music. At seven he came to the attention of Harry Connick Jr., who invited him to sit in at a show at Bally's Grand in Atlantic City, New Jersey. Connick later arranged for him to study in New Orleans with the pianist Ellis Marsalis, and in the summer of 1999 Cincotti toured with Connick. He was playing professionally in New York clubs by twelve, and he began singing to his own accompaniment around 1999, at fifteen or sixteen.

At the 2000 Montreux Jazz Festival he won a prize in the piano competition, with a performance of Dizzy Gillespie's "A Night in Tunisia." In 2001 he was cast in the off-Broadway tribute Our Sinatra, finished at the Horace Mann School and enrolled at Columbia University, where he graduated in 2005. In February 2002, at eighteen, he became the youngest performer to headline the Oak Room at the Algonquin Hotel in New York. The producer Phil Ramone heard him at Feinstein's at the Regency Hotel and agreed to make his first album.

Peter Cincotti (Concord, released March 11, 2003) was produced by Ramone and is a mix of standards, pop covers and originals, among them Fats Waller's "Ain't Misbehavin'," "Sway," "You Stepped Out of a Dream," a Nature Boy medley, "Spinning Wheel" and "Rainbow Connection." The originals include lyrics by his mother, Cynthia. Discogs credits Kenny Washington on drums and David Finck on bass. The record reached No. 1 on Billboard's jazz chart, which made Cincotti, then nineteen, the youngest musician to do so, and it peaked at No. 118 on the Billboard 200. A two-song Christmas single, My Favorite Time of Year, followed in 2003 with Barak Mori on bass and Scott Kreitzer on tenor saxophone.

On the Moon (Concord, September 2004) was again produced by Ramone and drew a stronger New York jazz cast: Kenny Washington and Mark McLean on drums, Mori on bass, Sam Yahel on keyboards, Wycliffe Gordon on trombone, Gary Smulyan on baritone saxophone, Brad Leali on alto saxophone, Barry Danielian on trumpet and Bashiri Johnson on percussion. Its twelve tracks pair "St. Louis Blues," "I Love Paris," "Bali Ha'i" and "Cherokee" with two Gerry Goffin and Carole King songs and several Cincotti originals, some co-written with his sister Pia. It reached No. 2 on Billboard's jazz chart, charted in France and Italy, and earned him a gold record in France. The concert DVD Live in New York followed, and in 2004 he also had a small role, and a place on the soundtrack, in the Bobby Darin film Beyond the Sea, and appeared as a piano player in Spider-Man 2.

After that his records turned toward pop and rock songwriting. The producer David Foster signed him to 143 Records, and East of Angel Town, made with Foster, Humberto Gatica and Jochem van der Saag and written with the lyricist John Bettis, came out in Europe on October 29, 2007 and in the United States in January 2009. Its single "Goodbye Philadelphia" reached the top ten on European pop radio, and the album reached No. 16 in France, where it was certified gold, and No. 5 on Billboard's jazz albums chart. He toured the United States with Seal and in 2008 appeared with the French DJ David Guetta on the finale of Star Academy performing "Love Is Gone." Metropolis (Heads Up, May 2012), produced by John Fields, moved further toward rock and dance-pop. In July 2012 he and his sister Pia presented the musical How Deep Is the Ocean? at the New York Musical Theatre Festival. In 2013 he sang "La Felicità" with Simona Molinari at the Sanremo Festival in Italy, and in 2014 he wrote, arranged and produced the soundtrack for Silvio Muccino's film Le leggi del desiderio. In 2015 he appeared as himself in the third season of the Netflix series House of Cards, singing a duet with the president, and joined Sting and Annie Lennox at the Old Vic gala in London.

His later albums are on his own label, Freddy Eggs Records. Long Way From Home (October 13, 2017) was written, arranged and produced by Cincotti, who moved his pianos to a house on the Jersey Shore and built a recording studio there. With Killer on the Keys (2023) he came back to the piano repertoire: a tribute to the great piano men and women, running from Scott Joplin's "The Entertainer" and Billy Joel's "New York State of Mind" to Lady Gaga's "Poker Face," with Obed Calvaire among the drummers. He has sold out several residencies at Café Carlyle in New York, where Town & Country called him a New York institution, and a live album from the room, Live at the Café Carlyle, was issued on vinyl in December 2024 with a repertoire drawn from his Concord years: "Raise the Roof," "Sway," "I Love Paris," "St Louis Blues," "How High the Moon." In May 2026 he released In Color: Part One, the first of three planned installments of all-original music, with guests including Angélique Kidjo and Marcus Miller; Chris Botti and Richard Marx are named among the collaborators on In Color. He is 43.

Cincotti is a pianist first. He has said he considers himself a piano player before a singer, that he began playing at three and singing at fifteen, and that playing and singing at once is a third skill he is still developing. AllMusic's biography describes a jazz-influenced pianist and vocalist with a leaning toward adult alternative pop and 1970s-style rock, and the arc of his records follows that description: standards and jazz-club arrangements on the first two Concord albums, a pop and rock songwriter from East of Angel Town onward, and a return to piano-led repertoire in 2023 and 2024. Ramone said he hears everything from Fats Waller on up in the way Cincotti listens, and critics early on set him beside Harry Connick Jr. and Frank Sinatra, whose songs he deliberately kept off his debut.

The jazz credentials are specific: a Montreux piano prize in 2000, study with Ellis Marsalis, a Billboard jazz chart No. 1 and No. 2 in successive Concord releases, and rhythm and horn sections on On the Moon drawn from working New York players. What separates him from the straight-ahead bandleaders is the repertoire and the audience. His originals, his Italian and French pop-chart presence and his film, television and fashion work place him closer to the singer-songwriters who started at the piano than to a bandleader who writes for a quartet, and Wikipedia calls him a singer-songwriter. That puts him in crossover territory, with vocal jazz and jazz pop the closest labels for the records themselves.