Giorgio Azzolini was born in La Spezia on March 25, 1928. According to the Saint Louis College of Music's jazz archive he started on the trumpet before moving to the double bass, and he studied in Florence with Antonio Godoli, the double bassist of the Stabile Orchestra Fiorentina; Italian Wikipedia adds that he then trained in Milan in harmony, composition and arranging. The archive says his first working years were spent on Italian and British ocean liners and with an international orchestra in Germany, and the introduction to his last interview, published by il manifesto in August 2024, says he first heard African American jazz in New York during transatlantic crossings.

He settled in Milan in the late 1950s. Discogs credits him from 1958, on the Enrico Intra Quintet's Welcome Mr. Swing (Liberty) with guitarist Bruno De Filippi, drummer Gianni Cazzola and pianist Enrico Intra, and on Intra's single with the singer Johnny Dorelli. The group that defined his career was the quintet of tenor saxophonist Gianni Basso and trumpeter Oscar Valdambrini, which Italian Wikipedia says he belonged to from its original formation and which a profile in Il Popolano has him anchoring from 1958 to 1971. Discogs documents the collaboration from the 1959 Basso Valdambrini Quintet LP (Music) through Walking In The Night (RCA, recorded May 25 and June 1, 1960, with pianist Renato Sellani and Cazzola) and The Best Modern Jazz In Italy 1962 (RCA Victor, a sextet with trombonist Dino Piana) to the group's Fonit sessions of December 1970.

In 1960 he made the earliest of his own-name records on Discogs, the Cetra EP Jazz In Italy N.1, recorded in Milan on March 25 with Attilio Donadio on alto and baritone saxophones and clarinet, Piana on valve trombone and drummer Franco Mondini. The same year Discogs has him on drummer Gil Cuppini's quintet LP, on the guitarist Franco Cerri's EP Blues For Franco and, on October 2, on the singer Helen Merrill's Milan session for Cetra with drummer Franco Tonani, Basso, Piana and Sellani. He is on the American altoist Buddy Collette's 1961 Milan sessions (collected by Fresh Sound in 2020) and on a run of sessions for other Milan leaders: Eraldo Volonté's My Point Of View (Durium, 1963), the Bossa Nova! LP for Ricordi that put Basso and Valdambrini with Sellani, Piana and Cerri in 1963, and Cerri's own 1963 and 1964 Columbia LPs.

His own records of the mid-1960s made him a leader of the Italian modernists. Tribute To Someone (Ciao! Ragazzi, recorded in Milan in 1964) has Piana, the trumpeter Franco Ambrosetti, the tenor saxophonist Gato Barbieri and pianist Sellani, and plays Herbie Hancock's title tune, Miles Davis's "So What," Benny Golson's "The Stroller" and Barbieri's "Hiroshima." In 1965 he was the featured bassist on Ambrosetti's Durium LP A Jazz Portrait Of Franco Ambrosetti, with pianist Franco D'Andrea. The trio he formed with D'Andrea and Tonani recorded What's Happening? at Milan's Fonorama Studio between March 29 and April 12, 1966; the Saint Louis archive says the trio played Intra's Club in Milan, the Sanremo Jazz Festival in March 1966 (alongside the American tenor saxophonist Booker Ervin) and the Lugano festival in 1967, and quotes Joachim-Ernst Berendt calling the record one of the most exciting European recordings of its year. On June 27, 1968, again at Fonorama, he led a quartet with trumpeter Enrico Rava, D'Andrea and drummer Aldo Romano for Crucial Moment, which Discogs tags as free jazz and avant-garde jazz; the six tracks include a ballad, "Giorvi," that the release text says he dedicated to his wife and daughter, and a trio reading of John Carisi's "Israel." A month earlier, in May 1968, he had been one of two bassists, with Benoit Charvet, on Volonté's free-jazz LP Free And Loose.

In the 1970s he moved to the front of larger ensembles. The Giorgio Azzolini Big Band (Dire, recorded in Milan in 1971) is a fourteen-piece band with Volonté and Basso on tenors, Giancarlo Barigozzi on saxophones and flute, Gianni Bedori on flute, Emilio Soana and Valdambrini in the trumpets, D'Andrea on piano and the Swiss drummer Pierre Favre; De Filippi plays sitar on "Bangkok." Discogs credits Azzolini with "Blues Deflection," "Bangkok" and "Galaxy" and with sharing the arranging credit with Angel "Pocho" Gatti and Giulio Libano. Azzolini's Spanish Portrait (Jazz D'Essai, dated 1973 on Discogs) is a quintet with the trumpeter Sergio Fanni, Volonté, D'Andrea and drummer Bruno Biriaco, and The Scicluna Street (Carosello, recorded at Studio 7 in Milan in 1976) is a quintet with Barigozzi, Fanni, drummer Tullio De Piscopo and pianist Sante Palumbo, with D'Andrea on two tracks. Two of those pieces, "Spanish Portrait" and "Blues Deflection," are also credited to him as composer on the live LP Capolinea Live Jazz, recorded at Milan's Capolinea club in December 1974. In the same years he was the bassist for the pianist Guido Manusardi's quartet at the Ljubljana jazz festival on June 9, 1972 (issued as Live Suite, BASF, with De Piscopo and saxophonist Claudio Fasoli), for the trombonist Slide Hampton's Life Music (Carosello, 1975) and for Fasoli's trio LP Eskimo Fakiro (Carosello, 1977, with D'Andrea and Biriaco), and he stayed in the Basso-Valdambrini orbit on records such as Cuppini's 1968 big-band LP Sof' Stroke and Afrodite by the Valdambrini-Piana Quintet (Vedette, 1977).

Alongside the jazz he worked steadily as a studio bassist. Discogs credits him on Ornella Vanoni's Ai Miei Amici Cantautori (Ariston, 1968), Gigliola Cinquetti's Su E Giù Per Le Montagne (1972) and Stasera Ballo Liscio (1973), Ivano Fossati's Il Grande Mare Che Avremmo Traversato (Cetra, 1973), Carmine Coppola's Il Padrino Parte II (Ariston, 1975), Milva's Canzoni Tra Le Due Guerre (recorded live at Milan's Piccolo Teatro in October 1977) and Astor Piazzolla's Milan sessions of December 1977; Italian Wikipedia says he also toured with Dorelli, Vanoni, Milva, Iva Zanicchi and the Quartetto Cetra. He taught double bass at the Scuola Civica di Jazz in Milan and wrote two books for Edizioni Curci, among them Jazz Bass: Tutto quello che il bassista jazz deve sapere. The bassist Stefano Senni's biography says he graduated from the Milan civic jazz courses under Azzolini's guidance.

He kept recording into old age. Giorgia Mood (Splasc(h), recorded at Barigozzi Studios on March 4 and 10, 1987) is a trio with Palumbo and drummer Alfredo Golino, with Azzolini also credited as producer. On March 23, 1996, in his home town's Toni Studio in La Spezia, he recorded Late Nite with David Ng's group, the saxophonist Andrea Imparato and Cuppini, for whom it was the last session credited on Discogs. Gerovijazz, profiling him in June 2010 at 82, describes his 2002 octet record A Walk Through My Life (CDpM Lion), made with the Bergamo pianist Claudio Angeleri, as his final work with Angeleri. His 1960s records came back on CD through the Rearward label, Tribute To Someone in 1998 and What's Happening? and Crucial Moment in 2000. He died in Milan on April 12, 2024, at 96; il manifesto ran the interview it billed as his last on August 17, 2024.

Azzolini's records span the two poles of Italian jazz in the 1960s and 1970s. With Basso and Valdambrini the Discogs style tags are bop, cool jazz, hard bop and modal; the 1960 Walking In The Night is tagged hard bop and modal, and the Saint Louis archive says the quintet's work included radio and television appearances as well as records and concerts. Under his own name the tags shift with the decade: modal on Tribute To Someone (1964), post-bop, modal and free jazz on What's Happening? (1966), free jazz, avant-garde jazz and modal on Crucial Moment (1968), big band on the 1971 album, and soul-jazz, fusion, modal and cool jazz on The Scicluna Street (1976). The Pino Candini liner notes quoted on the What's Happening? reissue say the trio married blues feeling to free syntax and call his bass playing powerful yet humble; the reissue's own text describes a seven-track program that mixes three free jazz pieces with standards, among them "When I Fall In Love" and Charlie Parker's "Moose The Mooche."

His writing for larger groups is on the 1971 album, where the magazine Jazzit, writing about Barigozzi's "Free Man," says the music sounds remarkably contemporary and names solos by Volonté, Barigozzi, D'Andrea, Azzolini and Favre, and where Discogs shows him sharing the arranging with Giulio Libano and the pianist Angel "Pocho" Gatti. He also led records built on other people's repertoire: Hancock, Davis and Golson on Tribute To Someone, and standards on Jazz In Italy N.1.

The pop and light-music sessions listed above are a real part of his working life, but they are not where his catalog sits: of the 122 Discogs entries carrying his credit, 99 are tagged jazz, and all nine records under his own name are jazz. He is treated here as a jazz bassist who worked as a session player, not the other way around.