Krzysztof Komeda was born Krzysztof Trzciński on April 27, 1931, in Poznań, the son of Mieczysław Trzciński and Zenobia (née Gębicka). He grew up in Częstochowa and Ostrów Wielkopolski, took piano lessons from early childhood, and at eight was accepted into the Poznań conservatory, a course of study the Second World War cut short. He kept working on theory and piano until 1950, when he finished secondary school in Ostrów, and then entered the Medical Academy in Poznań, where he took his medical degree in 1956 and chose otolaryngology as his specialty. Komeda was a stage name, a way of keeping his jazz playing apart from his daytime work at a medical clinic.

Jazz reached him through the swing bassist Witold Kujawski, whom he met in Ostrów and who took him to Kraków, where jam sessions in Kujawski's apartment drew the first generation of postwar Polish jazz players. He worked with the Melomani, the pioneering Kraków and Łódź group built around Jerzy Matuszkiewicz, Andrzej Trzaskowski and Kujawski, and with a Poznań group led by Jerzy Grzewiński that turned toward Dixieland. Modern jazz interested him more, and in 1956 he formed the Komeda Sextet with the saxophonist Jan "Ptaszyn" Wróblewski and the vibraphonist Jerzy Milian. The group made its name at the first Sopot Jazz Festival in August 1956 and was the first Polish band to play modern jazz, with a sound that combined the manner of the Modern Jazz Quartet, led by John Lewis, and the Gerry Mulligan Quartet. A silver medal at the International Youth Festival in Moscow followed in 1957.

That year also began his collaboration with the film director Roman Polański, for whose short Two Men and a Wardrobe (1958) he wrote his first film score. In 1958 he moved to Kraków, joined the Jazz Believers, and played the first Jazz Jamboree festival in Warsaw, an event he returned to every year until 1967. He led a trio, a quartet and a quintet whose lineups changed often; the saxophonist Michał Urbaniak was in the quintet from about 1962 to 1964, and the trumpeter Tomasz Stańko joined in 1963 and stayed until 1967. A first trip to Scandinavia in spring 1960 became an annual tour, with regular engagements at the Gyllene Cirkeln in Stockholm and the Jazzhus Montmartre in Copenhagen, and the Danish director Henning Carlsen commissioned scores for Hvad med os, The Cats and Hunger. His Ballet Etudes, first played at Jazz Jamboree in 1962 to a cool reception from Polish critics, opened doors abroad, and he recorded it in Copenhagen on May 3, 1963, for Metronome. In 1962 readers of the magazine Jazz named him jazzman of the year.

His score for Polański's first feature, Knife in the Water (1962), was played by a jazz group with the Swedish tenor saxophonist Bernt Rosengren, and its themes became the EP Crazy Girl. Three more Polański features followed: Cul-de-sac (1966), The Fearless Vampire Killers (1967) and Rosemary's Baby (1968). His own records of these years include Astigmatic, taped at the Warsaw Philharmonic on December 5 to 7, 1965, by a quintet with Stańko, the alto saxophonist Zbigniew Namysłowski, the German bassist Günter Lenz and the Swedish drummer Rune Carlsson, and issued by Muza in 1966. In 1967 he recorded a poetry-and-jazz album in Baden-Baden for a West German label and made his last sessions in Warsaw that autumn. For Jerzy Skolimowski's Le Départ (1967), a Philips EP of the score credits a group of musicians from the French and international scenes, among them Gato Barbieri, Don Cherry and Eddy Louiss. Film work was a large part of his output, more than sixty scores in all, but it grew out of the jazz group he led.

In January 1968 he went to the United States to score Rosemary's Baby and Buzz Kulik's The Riot. The lullaby that opens Rosemary's Baby, sung in the film by Mia Farrow, became his best-known melody. In December 1968, in Los Angeles, he fell down an escarpment while with the writer Marek Hłasko, an accident Polański later described in his memoirs as friendly roughhousing, and suffered a brain hematoma. Treatment in a Los Angeles hospital did not save him. His wife Zofia, whom he had married in 1958, brought him home to Poland in a coma in April 1969, and he passed away in Warsaw on April 23, 1969, aged 37. He is buried at Powązki Cemetery in Warsaw. Hłasko, who was tormented by guilt, died two months later.

Komeda is regarded as a founding figure of what is often called the Polish school of jazz. A street in Warsaw's Mokotów district has carried his name since 1991, the Komeda Jazz Festival has been held in Słupsk since 1995, the National Bank of Poland issued a commemorative coin in 2010, a statue was unveiled in Poznań the same year, and a crater on Mercury was named for him in 2012. Zofia Komeda compiled and produced many of his archival releases. Later musicians have recorded his music, among them Stańko's septet on Litania (ECM, 1997), with bassist Palle Danielsson, and Leszek Możdżer's solo album Komeda (ACT, 2011).

Komeda played jazz that drew on European traditions, with Slavic lyricism, Polish folk and classical colors, and a poet's sense of mood, and he is credited with opening a path away from the American model that dominated European jazz in the 1950s. His early sextet owed a debt to the Modern Jazz Quartet and the Gerry Mulligan Quartet, but Astigmatic moved far from that: its three long pieces combine modal playing, free-jazz-inspired improvisation, tone clusters, aleatoric passages and a dramatic, late-Romantic lyricism. The Penguin Guide to Jazz called it one of the finest jazz albums made in Europe, the critic Stuart Nicholson saw in it a shift toward a specific European aesthetic, and Manfred Eicher, founder of ECM Records, described it as a milestone; readers of the Polish magazine Jazz Forum once voted it the best album of all time. His film music was written in the same voice and often played by his own jazz groups, and pieces such as "Sleep Safe and Warm," the lullaby from Rosemary's Baby, were later recorded by other jazz musicians. Polish musicians including Urszula Dudziak, Michał Urbaniak and Tomasz Stańko have reinterpreted the music of Astigmatic, and the Komeda Jazz Festival and its composers' competition were started by the pianist and composer Leszek Kułakowski.