Abbasa bint Sulayman (Arabic: العباسة بنت سليمان) was an Abbasid princess, daughter of Sulayman ibn Abi Ja'far, niece of Abbasid caliph al-Mahdi and wife of caliph Harun al-Rashid.
Her father, Sulayman was a son of the Abbasid caliph al-Mansur (r. 754–775) and one of his wives, Fatima bint Muhammad, granddaughter of Isa ibn Talha al-Taymi, who was the son of a leading companion of the Islamic prophet Muhammad, Talha ibn Ubaydallah.
[1][3] Abbasa was related to Abbasid house both by birth and marriage.
She was the daughter of Abdallah ibn Muhammad, and had descended from Uthman, the third Caliph of the Rashidun.
[2] Abbasa was contemporary and related to several Abbasid caliphs, prince and princesses.