The 10.5 cm leFH 18/40 supplemented the 10.5 cm leFH 18 and the 10.5 cm leFH 18M as the standard divisional field howitzer used during the Second World War. It was designed in an effort to lighten the weight of the 105 mm artillery piece and to make it easier to produce. Generally it did not equip independent artillery battalions until after the Battle of Stalingrad in 1943. Some were also exported to Finland, where they were known as 105 H 33-40. The Romanian Army acquired a number of leFH 18/40 in 1943, to make up for the losses in artillery suffered during the Battle of Stalingrad. 

 The leFH 18/40 howitzer in a concealed firing position in Italy, 1944. In March 1942 a requirement was issued for a lighter howitzer by the Wehrmacht that must also be ready as soon as possible and capable of rapid production. This requirement was met by mounting the barrel of the leFH 18M on the carriage for a 7.5 cm PaK 40 antitank gun. The new carriage used torsion bars running the full length of the carriage to suspend the wheels. The original wheels of the PaK 40 mounting were too small for use by the howitzer and were replaced by larger pressed-steel wheels with solid rubber tires. The new mounting increased the rate of fire as well as making the howitzer somewhat lighter. The leFH 18/40 shared the different muzzle brakes used by the leFH 18M.