The Cooper T45 was an open-wheel formula racing car, developed and built by the Cooper Car Company in 1958, and designed by Owen Maddock. It competed in Formula 2 racing as well as in Formula One racing, where it won one World Championship Grand Prix, the 1958 Monaco Grand Prix, being driven by Maurice Trintignant.

The 1958 Monaco Grand Prix was a Formula One motor race held on 18 May 1958 at Monaco. It was race 2 of 11 in the 1958 World Championship of Drivers and race 2 of 10 in the 1958 International Cup for Formula One Manufacturers. The race was the 16th Monaco Grand Prix and was held over 100 laps of the three kilometre circuit for a total race distance of 314 kilometres.