12 Concerti a cinque (op. 9) is a collection of concertos by the Italian composer Tomaso Albinoni, published in 1722.

The most famous piece from Albinoni's Opus 9 is the Concerto in D minor for oboe (Opus 9, Number 2). It is known for its slow movement. This concerto is probably the second best-known work of Albinoni after the Adagio in G minor (which was once believed to be a reconstruction based on a fragment by Albinoni). The concertos were dedicated to Maximilian II Emanuel, Elector of Bavaria, and were first published in Amsterdam. It is possible, but not certain, that they were written in the Elector's court during a 1722 visit there by Albinoni during performances of his theatrical compositions.