The SMArt 155 is a German 155 mm artillery round designed for a long-range, indirect fire top-attack role against armoured vehicles. The projectile was developed in 1989 by Diehl BGT Defence in Überlingen, Germany, with Rheinmetall and started full-rate production for the German Army in 1998. It consists of a 47-kilogram (104 lb) heavy artillery projectile containing two autonomous, sensor-fused, "fire-and-forget" submunitions. Due to the submunitions, it has been considered by some to be a cluster munition. As of 2008, representatives of the German defense ministry have referred to it as not being classified as submunition weapons, which were prohibited by the 2008 Convention on Cluster Munitions.

155 mm is a NATO-standard artillery shell caliber that is used in many field guns, howitzers, and gun-howitzers. It is defined in AOP-29 part 1 with reference to STANAG 4425.