Monica is of disputed etymology — possibly Berber from her North African origin, or from the Latin monere ("to advise, counsel"). Saint Monica (c. 332-387) — Berber Christian mother of Saint Augustine of Hippo whose decades of prayer and weeping are credited with her son's conversion to Christianity at age 32. *Their conversation at Ostia just before her death — described in Book IX of Augustine's Confessions — is among the most famous mother-son scenes in Christian literature. A top-50 US baby name from 1975 to 1992. Monica Bellucci (born 1964) — Italian actress and model. Monica Seles (born 1973)* — Yugoslav-American tennis champion; nine Grand Slam titles.
Subject of Augustine's Confessions (Book IX) and Garry Wills's Saint Augustine (1999).
In Pythagorean numerology the letters of Monica reduce to 1, The Leader. This is a traditional interpretive system, not a factual claim about the name.