The Type 10 grenade discharger (十年式擲弾筒, Juu-nen-shiki tekidantō) was a Japanese smoothbore, muzzle loaded weapon used during the Second World War.

The Type 10 has a range of 175 m (191 yd), greater than other grenade dischargers of that time.

Due to a translation error, the Type 10 was called the "knee mortar" by the Americans.

American troops on Guadalcanal became aware of the name "knee mortar" and thought the light design allowed it to be fired with the base plate resting on the thigh.

World War II era US intelligence thought that the weapon was primarily used to discharge signal flares, the larger and heavier Type 89 grenade discharger being used to fire explosive rounds instead.