The United Kingdom's L16 81mm mortar is the standard mortar used by the British armed forces. It originated as a joint design by the UK and Canada. The version produced and used by Australia is named the F2 81mm Mortar, whilst the version used by the U.S. armed forces is known as the M252.

It was introduced in 1965/6, replacing the Ordnance ML 3 inch Mortar in UK service, where it is used by the Army, the Royal Marines and the RAF Regiment.

In UK armoured/mechanised infantry battalions, the L16 mortar is mounted in an FV 432 AFV (six[1] per battalion mortar platoon). British army light role infantry battalions and the Royal Marines may transport their mortars in BvS 10 vehicles (the replacement for the Bv 206). Otherwise, it is carried dissassembled in three loads, (barrel, baseplate and bipod with sights, each approximately 11 kg), normally carried by a vehicle or helicopter and assembled for firing from the ground.

The weapon can be man-packed by the mortar detachment, in which case the ammunition would be carried by other soldiers of the battalion. In addition to their normal equipment, each soldier would carry four bombs in a pair of two-bomb, plastic containers (known as greenies in the British Army).

The mortar has been used by many countries' armed forces.