Saint Marcellina (c. 330 – 398) was born in Trier, Gaul around the year 330 as a member of a Catholic family. She was the only sister of Saint Ambrose of Milan, older sister of two brothers, and daughter to a man who resided as Praetorian prefecture of Gaul. Marcellina received the veil of consecrated virginity to live a life of perpetual virginity and to devote herself to the practice of prayer and asceticism.

After living life as part of a pious family, Saint Marcellina would die roughly around 398. Honored as a saint, her body would be buried in the crypt under the altar of the Ambrosian Basilica.

Saint Marcellina made the decision to dedicate her life to an attitude of piety and holy virtue. She sought with every inch of her heart to illustrate the utmost amount of humility and respect to herself and all around her. As the eldest sister in her family, she made it a point to pass her already established virtuous traits down to her younger brothers by teaching them such principles that forbade the pursuit of self empowerment by knowledge. She implemented in them the "desire not to express their virtue, but to become truly virtuous." This life she led call for continual abstinence, dedication to prayer, strict fasting, etc. This life chosen by Saint Marcellina is one of great sacrifice and can define an individual as truly humble.

Marcellina is a comune (municipality) in the province of Rome in the Italian region Latium, located about 30 km northeast of Rome.