The Essonne () is a long French river. It is a left
tributary
A tributary, or an ''affluent'', is a stream or river that flows into a larger stream (''main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which they ...
of the
Seine
The Seine ( , ) is a river in northern France. Its drainage basin is in the Paris Basin (a geological relative lowland) covering most of northern France. It rises at Source-Seine, northwest of Dijon in northeastern France in the Langres plat ...
. Its course crosses the departments of Loiret and Essonne, and it gives its name to the latter. The Essone's name and the present name of its higher course (the Å’uf) originate in Acionna, a Gallo-Roman river goddess attested at