The name Mercedez is of Spanish origin, derived from the Spanish word "merced," which means "grace" or "mercy." It has its roots in the Latin word "merces," meaning "reward" or "payment."

In the 13th century, the name was associated with the Spanish religious order of "Nuestra Señora de la Merced" (Our Lady of Mercy), which was founded in Barcelona in 1218. The order's mission was to ransom Christian captives from the Moors during the Reconquista. The name gained popularity as a name for girls born into families with ties to this religious order.

One of the earliest recorded instances of the name Mercedez dates back to the late 15th century. Mercedez de Velasco y Aragón was a Spanish noblewoman born in 1485, who served as a lady-in-waiting to Queen Isabella I of Castile.

In the 16th century, Mercedez de San Salvador was a Peruvian nun and missionary who played a significant role in the evangelization of the indigenous people of Peru. She was born in 1542 and died in 1601.

During the 17th century, Mercedez de Velasco y Tovar, born in 1620, was a Spanish noblewoman and the wife of the Viceroy of Peru, Diego de Benavides y de la Cueva.

In the 19th century, Mercedez de Santa Cruz y Montalvo, born in 1789, was a Spanish writer and journalist who was known for her contributions to the Romantic literary movement in Spain.

Another notable figure with the name Mercedez was Mercedez Pavlovich de Frers, an Argentine artist and painter born in 1888. She was known for her landscape paintings and portraits, and her works are part of several museum collections in Argentina.

While the name Mercedez has its origins in Spain and was initially associated with religious and noble families, it has since become a popular name in many Spanish-speaking countries and beyond. The name's meaning of "grace" or "mercy" has contributed to its enduring appeal as a beautiful and meaningful choice for baby girls.