A carabinier (also sometimes spelled carabineer or carbineer) is in principle a soldier armed with a carbine. A carbiniere is a carabiniere musket or rifle and was commonplace by the beginning of the Napoleonic Wars in Europe. The word is derived from the identical French word carabinier.

Historically, carabiniers were generally (but not always) horse soldiers. The carbine was considered a more appropriate firearm for a horseman than a full-length musket, since it was lighter and easier to handle while on horseback. Light infantry sometimes carried carbines because they are less encumbering when moving rapidly, especially through vegetation, but in most armies the tendency was to equip light infantry with longer-range weapons such as rifles rather than shorter-range weapons such as carbines. In Italy and Spain, carbines were considered suitable equipment for soldiers with policing roles, so the term carabinier evolved to sometimes denote gendarmes and border guards.

Today, the term is used by some countries in military, law enforcement, and gendarmerie roles.