Baraka bint Thaʿlaba (Arabic: بَـرَكَـة بنت ثَعلَبَة), commonly known by her kunya Umm Ayman (Arabic: أمّ أيمن), was an early Muslim and companion of the Islamic prophet Muhammad.
She was an Abyssinian slave of Muhammad's parents, Abdullah ibn Abd al-Muttalib and Aminah bint Wahb. Following the death of Aminah, Baraka helped to raise Muhammad in the household of his grandfather, Abd Al-Muttalib ibn Hashim. He saw her as a mother figure. Muhammad later freed her from slavery, but she continued to serve Muhammad and his family. She was an early convert to Islam, and was present at the important battles of Uhud and Khaybar.
Following her freedom Muhammad also arranged her marriages, first to Ubayd ibn Zayd of the Banu Khazraj, with whom she had a son, Ayman ibn Ubayd, giving her the kunya Umm Ayman (meaning mother of Ayman). She was later married to the adopted son of Muhammad, Zayd ibn Harithah. Her son with Zayd, Usama ibn Zayd, served as a commander in the early Muslim army and led the Expedition of Usama bin Zayd into the Byzantine Empire.