The Projector, Infantry, Anti Tank (PIAT) Mk I was a British man-portable anti-tank weapon developed during the Second World War. The PIAT was designed in 1942 in response to the British Army's need for a more effective infantry anti-tank weapon and entered service in 1943.

Lieutenant-Colonel Latham Valentine Stewart Blacker OBE was a British Army officer and inventor of weapons; he invented the Blacker Bombard, from which was developed the Hedgehog anti-submarine spigot-mortar – and laid the basis of the PIAT anti-tank weapon.