The Aresaces were a Celtic people closely related to, and probably originally part of, the Treveri. They inhabited the left bank of the Rhine in the Mainz-Bingen area, which was once the easternmost part of Treveran territory.
The Aresaces are not mentioned by ancient writers, such as geographers or Julius Caesar, but are known from three inscriptions dating to the 1st and 2nd centuries CE. Two of these come from Rhenish Hesse, while the third is from Augusta Treverorum (Trier), the capital of the Treveri.
A grave monument from Mainz-Weisenau that identifies the two deceased children as Treveri has been explained as evidence that the Aresaces continued to regard themselves as a subdivision of the Treveri.
Another Celtic tribe in Rhenish Hesse, known from an inscription as well as ancient literature, was the Cairacates.
According to current scholarship, the Aresaces would have been organized as a pagus or sub-unit of the Treveri, settled in Rhenish Hesse in the area south and east of Mainz. Their neighbours to the south were the Celtic Mediomatrici, while on the opposite bank of Rhine dwelled the Germanic Vangiones, Triboci, Nemetes, and the Mattiaci (a subdivision of the Chatti) in the area around present-day Wiesbaden.
This area was only sparsely settled during the late La Tène period, with larger settlements barely to be found in the second half of the 1st century BCE. One possible cultural and administrative centre of the Aresaces might have been the oppidum on the Donnersberg, which would have marked the southeasternmost centre of Treveran influence. Urbanization was only to increase noticeably at the time of, or shortly before, the Roman presence in the region.