The 3rd Marine Infantry Regiment () is a unit of the French Army in the French Forces. The 3e RIMa is one of the oldest of the troupes de marine. This regiment is one of the "Quatre Grands" of marine infantry once garrisoned within the four military ports, ready to embark : the « Grand Un », the « Grand Deux », the « Grand Trois » and the « Grand Quatre ». The « Grand Trois » has participated actively to the various far expeditions of the 19th century in Africa, the Americas, Oceania and the Orient. Surnamed also the "3rd Marine", the unit was part of the « Blue Division » which illustrated capability at the Battle of Bazeilles on August 31 and September 1, 1870. The regiment was subordinated to the 9th Marine Infantry Brigade.