Giacomo Rust or Rusti (1741 in Rome, Italy – 1786 in Barcelona, Spain) was an Italian opera composer, probably of German ancestry.
Not a great deal is known about Rust. Between 1763 and 1777, Rust was active in Venice, where his first opera, a dramma giocoso, La contadina in corte, to a libretto by Niccolò Tassi, was performed in 1763. During this period, Rust acquired great fame as opera composer, not only in Italy, buy also abroad, which gained him an invitation to be employed in the service of the archbishop of Salzburg. On 12 June 1777, he was named a choir master at the Salzburg court, a post that he abandoned towards the end of the year. Some time later, Rust returned to Venice to continue his operatic activity. In 1783, he settled down in Barcelona, where he assumed the office of the Maestro de capilla.
The following is the list of the operas composed by Rust.