The T18 Boarhound was an American heavy armored car produced in small numbers for the British Army during the Second World War.

In July 1941, the United States Army Ordnance Corps issued specifications for a heavy armored car (along with another specification for a medium armored car, which resulted in the T17 Deerhound and T17E1 Staghound) to be built for supply to the British.

By then, it was clear that the anti-tank performance of the 37 mm gun was insufficient and the production version, the T18E2, which was named Boarhound by the British, received the 57 mm gun M1, the US-manufactured variant of the British QF 6 pounder.

Late in 1942, orders were issued for upwards of some eight Boarhounds to be assigned to the Eighth Army, which used them sparingly as supporting armored vehicles and, to some extent, in reconnaissance roles.

At 80 kilometers an hour, it did have a relatively high-top speed, but acceleration and turning were hampered by the somewhat thick frontal armor, which could reach 40mm in some places.