A septet is a formation containing exactly seven members. It is commonly associated with musical groups but can be applied to any situation where seven similar or related objects are considered a single unit, such as a seven-line stanza of poetry.

The Septet in E♭ major, Op. 65, was written by Camille Saint-Saëns between 1879 and 1880 for the unusual combination of trumpet, two violins, viola, cello, double bass and piano. Like the suites Opp. 16, 49, 90, the septet is a neoclassical work that revives 17th-century French dance forms, reflecting Saint-Saëns's interest in the largely forgotten French musical traditions of the 17th century. The work was dedicated to Émile Lemoine, a mathematician and founder of the chamber music society La Trompette, who had long requested Saint-Saëns to compose a piece featuring the trumpet.