T-84 is a Ukrainian main battle tank (MBT) based on the Soviet T-80 main battle tank.

T-84 was designed by Kharkiv Morozov Machine-Building Design Bureau (KMDB) between 1993 and 1994 and was manufactured at Malyshev Factory in Kharkiv from 1994.

T-84 entered service with the Ukrainian Army in 1999 and further developed into T-84 Oplot.

T-84 Oplot has a mass of 51 tonnes, a length of 7.075 m (23 ft 3 in), and a width of 3.400 m (11 ft 2 in).

With a height of 2.800 m (9 ft 2 in), it has a ground clearance of 0.50 m (1 ft 8 in).

The Oplot has a crew of three (3) including the commander, the gunner, and the driver.

T-84 Oplot has modular composite armor plus ERA, and is also equipped with an active protection system.

The main armament consists of a 125 mm smoothbore KBA-3 cannon with 46 rounds.

As a secondary armament T-84 has a 12.7 mm (.50) KT-12.7 anti-aircraft machine gun with 450 rounds and a 7.62 mm (.308) KT-7.62 coaxial machine gun with 1250 rounds.

T-84 Oplot is powered by either a 1,200 hp KMDB 6TD-2E opposed piston 6-cylinder (12 pistons) diesel engine or by a 1,500 hp KMDB 6TD-3 opposed piston 6-cylinder diesel engine.

The model equipped with the KMDB 6TD-2E engine has a power-to-weight ratio of 24.7 hp/t, while the variant equipped with the mode powerful KMDB 6TD-3 engine has a power-to-weight ratio of 30 hp/t.

T-84 Oplot has an automatic transmission and uses a torsion bar suspension.

With a fuel capacity of 1,140 liters (250 imp gal; 300 US gal), the Ukrainian Oplot has an operational range of 500 km (310 mi) and a maximum speed of 70 km/h (43 mph) on-road and 45 km/h (28 mph) off-road.