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 Riband 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 event was part of the FIM Motorcycle Grand Prix World Championship from 1949 to 1976, before being transferred to the United Kingdom after safety concerns, becoming the British Grand Prix under the FIM from the 1977 GP season.