Tatra T815 is a family of trucks manufactured by the Czech company Tatra. It uses the traditional Tatra rigid keel tube concept and swinging half-axles that provide independent suspension. The vehicles are available in 4x4, 6x6, 8x8, 10x8, 10x10, 12x8 and 12x12 models. Both air-cooled and liquid-cooled engines are available with power ranging from 230–440 kilowatts (310–590 hp). While the successor to the Tatra T813 was originally designed for extreme terrain conditions, nowadays there are variants designed for mixed (both off-road and road) use.

The T815 and its descendant models led Czech truck racer Karel Loprais to victories six times in the Dakar Rally.

Designed to eventually replace T148 the prototype T157 was introduced in 1970 and several more prototypes were designed between 1970 and 1974 period but no production resulted. Due to protests from another Czechoslovak manufacturer LIAZ which was assigned by the government central planning committee to manufacture trucks of similar class Tatra dropped the T157 and instead started to concentrate on a heavier class as the replacement for T813 and T148 which was introduced in 1983 as T815 series. In 1989 Tatra modernized T815 series and introduced new T815-2 which received further upgrade in 1994 and just 3 years later in 1997 the new cabin TerrN°1 is introduced. Another facelift followed in 2000 where changes included among others new instrument panel and cab attachment and for the first time there is an option for fitment of liquid-cooled engines. The latest facelift of cabin came in July 2010. Due to emission requirements changes in 2003 Tatra developed all new V8 engine T3C to comply with Euro III where it followed the tradition once again with its air cooling design. The further developed T3D engine was introduced in 2006 with its SCR and Euro IV compliance.