ANCASTA. An obscure Romano-Brython goddess. She is mentioned on a single inscription from Clavsentvm (Bitterne) in Hampshire. The altar inscription dedicated to her reads: DEAE ANCASTAE GEMINVS MANI VSLM (To the goddess Ancasta, Geminus Mani[lius] willingly and deservedly fulfils his vow), which represents the only known dedication to this goddess.

Ancasta is known because of the inscription above and as such was probably a local deity. However, by comparison with the re-construction of proto-Celtic the goddess' name can be broken down into the components *an-kast-a- (very swift one). It may be that she was a river goddess, asssociated with the River Itchen (which would certainly fit with the interpretation of her name though this is merely speculative).