Claudio Ambrosini (born 9 April 1948) is an Italian composer and conductor.

He studied foreign languages and literature at the Università di Milano graduating with an MA in 1972. Afterwards, he studied electronic music with Alvise Vidolin at the Venice Conservatory from 1972 to 1975. He also studied early instruments there from 1975 to 1978 and music history at the Università di Venezia, where he got an MA in 1978. He was influenced in his compositions by his encounters with Bruno Maderna and Luigi Nono.

He won the Prix de Rome in 1985. In 1986 he represented Italy at the UNESCO International Rostrum of Composers. In 2007 he received the Leone d'Oro per la Musica at the Biennale di Venezia. He has received commissions from RAI, WDR, the French government, the Teatro La Fenice, the Accademia Filarmonica Romana and from other institutions.

He has worked for the Centro per la Sonologia Computazionale in Padova since 1976. He is professor with the department of Information Engineering of the University of Padova. In 1979 he founded the Ex Novo Ensemble in Venice, which is dedicated to the execution of contemporary music. In 1983 he founded the Centro Internazionale per la Ricerca Strumentale, where he is still director.