Stratonice (Greek: Στρατονίκη; fl. 3rd century BC) was a Syrian Greek Princess of the Seleucid Empire. Stratonice was of Greek Macedonian and Persian descent. She was one of the daughters born to the Seleucid Monarchs Antiochus II Theos and Laodice I. Among her brothers was the Seleucid King Seleucus II Callinicus and prince Antiochus Hierax.
Between 255 BC-250 BC, Antiochus II Theos recognized the Seleucid client state of Cappadocia to become an independent kingdom. In 255 BC, Ariarathes III of Cappadocia who co-ruled with his father, proclaimed himself as the first king of Cappadocia. Later that year, Antiochus II Theos arranged for Stratonice to marry Ariarathes III.
Through her marriage to Ariarathes III, Stratonice became the first Queen of Cappadocia. Stratonice and Ariarathes III, had a son called Ariarathes IV of Cappadocia who later succeeded his father as King. Ariarathes IV later married his maternal second cousin Antiochis.