Arsinoe of Macedonia (Greek: Ἀρσινόη; lived 4th century BC) was the mother of Ptolemy I Soter (323 BC – 283 BC), king of Egypt.
She was originally a concubine of Philip II, king of Macedon, and it is said she was given by Philip to Lagus/Lagos, a Macedonian, while she was pregnant with Ptolemy I Soter I, but it is possible that this is a later myth fabricated to glorify the Ptolemaic Dynasty. Ptolemy was regarded by the Macedonians as the son of Philip.
She was the daughter of Meleager and granddaughter of Balacrus, who was thought to be the son of Amyntas, the father of Alexander I of Macedon.
This article incorporates text from a publication now in the public domain: Smith, William, ed. (1870). "". Dictionary of Greek and Roman Biography and Mythology.