The Triumph GT6 is a 6-cylinder sports coupé built by Standard-Triumph, based on their popular Triumph Spitfire convertible. Production ran from 1966 to 1973.

The Triumph Six Cylinder or Triumph I6 engine is a cast-iron overhead valve straight-six engine produced by Standard Triumph. It is an evolution of the Standard Motor Company's inline-4 Standard Eight, with the addition of two cylinders and a larger displacement.