Arcadia (3 April 400 – 444) was the third daughter of Emperor Arcadius and Aelia Eudoxia and a member of the Theodosian dynasty.
Her next sibling was the male heir and future Emperor Theodosius II. Following the example of her older sister Aelia Pulcheria she took a vow of virginity, but unlike her never got married, devoting herself to religion. In Constantinople, she ordered the construction, near the Gate of Saturninus, of a monastery dedicated to Saint Andrew. The building, named also Rodophylion (Greek: Ροδοφύλιον) lay about 600 m. west of the gate. Heavily transformed, the church of the monastery is now the Koca Mustafa Pasha Mosque of Istanbul.