March battalion (French Bataillon de Marche, Polish Batalion marszowy, German Marschbatallion) is a battalion-sized military unit formed of all the rear-echelon units of an infantry regiment. It usually includes all the tabors, field kitchen staff, reserve soldiers, military police, commander's reserves, guards, aides, and raw recruits who did not arrive at the mobilization centre before the unit to which they were attached left for the front.

Alternatively, the name can be used for all provisional units made up of companies from various battalions for the purpose of giving them a command structure during their march.

The name is derived from the fact that such battalions are usually left in the barracks after the regiment has left for the front, and spend some time there to gather all the late-comers and volunteers. Then the unit follows the main force of the regiment, usually by fast, forced march.

March battalions were used extensively by many European armies of the 19th and 20th century, most notably British, Polish, German and French. The nature of modern conflicts, the change from conscript to professional armies, as well as innovations in the field of logistics make the march battalions obsolete.