Trimithis (Greek, Ancient (to 1453);: Τριμιθις) was an ancient Egyptian city in the Dakhla Oasis in the Western Desert. The site of the city is today known as Amheida (Arabic: أمحيدة) and is located in the New Valley Governorate of Egypt. The Greek name of the city, Trimithis, comes from the Coptic Trimhite, meaning "northern storehouse". The modern Arabic name, also spelled Amhâdeh or Amhida, is probably derived from either the Greek or Coptic.
Archaeological remains from the Old Kingdom have been found at Amheida. There was a template the site during the New Kingdom and a stela of Seti II has also been found. Habitation at the site increased exponentially under the Roman rule. Trimithis became a recognized polis (city). It declined rapidly in late antiquity. The Roman city was built around a temple of Thoth. Including its cemetery, it covered an area of at least 2.5km×1.5kmkm (01.6miles×00.9mileskm).
Bernardino Drovetti described the site in 1821. John Gardner Wilkinson, who saw it in 1825, was the first to record its modern name, as Lémhada, in 1843. Archaeological investigation of the site began under Ahmed Fakhry in 1963.