The F-5TH TCU (Third Capability Upgrade), also known as the F-5TH Super Tigris, is the third modernisation of the American F-5E fighter-bomber by the Thai military. The modernisation programme began in 2015 due to financial constraints which necessitated the Royal Thai Air Force keeping the ageing F-5T SCU in service. The F-5TH programme was jointly conducted by the Israeli company Elbit (which had worked on the F-5T in the late 1990s) and the Thai company RV Connext. The modernisation includes the new EL/M-2032 radar in place of one of the 20 mm guns, the Link-T/TH tactical datalink developed by the RTAF, the addition of the LITENING III targeting pod, and compatibility with AIM-9M, Python 4, and Derby missiles. The F-5TH is expected to remain in service until the early 2030s.

The Thai F-5TH TCU was introduced in Update "Tusk Force" as part of the Japanese air tree. It is a further upgrade from the F-5T SCU with even more ordnance options. In exchange for one of the 20 mm guns, the F-5TH gains the ability to use a wide variety of air-to-air and air-to-ground weapons. The aircraft's arsenal includes several active radar-homing and infrared-homing air-to-air missiles, including a pair of BVR-capable Derby missiles. For ground attack purposes, the F-5TH features an additional selection of guided munitions, as well as improved HMD targeting with thermal and NVD. However, as it is commonly pitted against Gen 4 fighters, the F-5TH's airframe begins to show its age, as it often struggles to keep up with faster opposition in a dogfight due to its limited top speed and acceleration.