The Southern 100 is a motorcycle road racing event held on the Isle of Man in July of each year.

[4] The meeting that year had 73 entrants, with the first race held, the 350 cc event, won by Manxman Derek Ennett.

[1] In 1958, the event was granted "National Status" and eleven years later was included in the British Championships.

[5] The races were part of the Irish Regal Championships in 1992 and 1993,[4] and is now one of five FIM-sanctioned International meetings in the British Isles.

[7] The Billown Circuit has been lapped with an average speed over 100 miles per hour (160 km/h) on a number of occasions, but it was first achieved by Dave Leech in the 1989 Southern 100 Solo Championship Race riding a 1000 cc Yamaha at an average speed of 100.26 mph.