The Theodore TR1 was a racecar which was designer by Ron Tauranac in 1978 and raced in the 1978 Formula One season.

The car made its first appearance at the 1978 Aregntine Grand Prix being driven by Eddie Cheever. The other driver of the car was Keke Rosberg.

The TR1 had a Ford Cosworth DFV V8 engine and Goodyear tyres. The car had a monocoque aluminium chassis and a Hewland FGA 400 six-speed gearbox.

The car was not successful, only qualifying for one of the races it entered, where it came 24th.