National hunt jockey, who has ridden 1000 winners. Born in Dundee, Niven became a jockey at the relatively senior age of 21, with his first win on the horse Loch Brandy at Sedgefield (Northern England) in May 1984.
Niven began a long-standing and successful partnership with trainer Mary Reveley in 1985. He rode horses including Cab On Target, Marello, Sybillin, Monsieur Le Cure who he rode to victory in the Royal & Sun Alliance Chase at the Cheltenham Festival (1994) and Ask Tom, on whom he won the Sandeman Maghull Novices' Chase at the Aintree Festival (1996). Niven broke his neck in a fall at Sedgefield in December 1999, but returned in 2001 to ride his 1000th winner, becoming only the 6th British jockey to achieve this number, and the first Scot.