The Senior Tourist Trophy is a motorcycle road race that takes place during the Isle of Man TT festival, an annual event traditionally held over the last week in May and the first week in June. The Senior TT is the blue ribbon event of the festival that takes place on the Friday of race week, with "The Marquis de Mouzilly St. Mars trophy" awarded to the winner.

The Isle of Man TT or Tourist Trophy races are an annual motorcycle racing event run on the Isle of Man in May and June of most years since its inaugural race in 1907. The event begins on the UK Spring Bank Holiday at the end of May and runs for thirteen days. It is often called one of the most dangerous racing events in the world as many competitors have died.