Aristomenes of Alyzia or Aristomenes the Acarnanian (born 3rd century BC; died 2nd century BC) was regent and chief minister of Egypt in the Ptolemaic period during the reign of the boy king Ptolemy V.
Aristomenes, son of Menneas, was a native of the city of Alyzia in Acarnania, Greece. He migrated to Egypt some time after 216 BC and became regent in 201 BC, supplanting Tlepolemus. In 197/196 BC, when Ptolemy V at the age of 12 took personal control of the kingdom, Aristomenes remained chief minister; this was his role when the "Memphis Decree" (recorded on the Rosetta Stone) was issued in March 196. He fell from power, for unknown reasons, in 192 BC.