The Malyshev Plant (ZiM) based in Kharkiv was one of the most important tank factories of the USSR and was responsible for producing Soviet tanks like the T-64 and T-80. Following the independence of Ukraine in 1991, it developed an indigenous version of the T-80 known as the T-84. The T-84's hull is based on that of the T-80UD variant and retains is basic layout, with the main difference being the substitution of the original gas turbine engine for a more fuel-efficient diesel 6TD engine which also gives it one of the best power-to-weight ratios in a main battle tank. The original cast turret has also been replaced by a new all-welded design composed of steel and composite armor. Reactive armor is also typically installed in both the hull and turret. Armament is initially identical to that of the T-80, based on a 125-mm KBA-3 smoothbore gun (a locally-built version of the 2A45M-1) fed by an automatic loader. It can fire the same ammunition as that of a T-80 and T-72 as well as a locally-designed Combat ATGM. Newer variants are quipped with a NATO-standard 120-mm smoothbore. Defensive armament consists of coaxial 7.62-mm PKT and turret-mounted 12.7-mm NSVT machine guns, and an active protection system is also equipped. The T-84 became the first tank to be received to the Ukrainian army after independence but only a handful of vehicles have been delivered. The main user has been Thailand which so far is the only export client, although Pakistan has planned to upgrade its T-80UDs to T-84 standard.

Development a new tank based on the T-80UD began in 1993 and resulted in the T-84. Equipment upgrades along with Kontakt-5 ERA resulted in the T-84U which was further developed into the T-84-120 Oplot which features a NATO-standard 120-mm gun, Duplet ERA, Zaslin APS, and a new PNK-6 panoramic tank sight. An IFV, ARV and SPAAG based on the T-84 have also been proposed but have not been developed.