Mullins comes from one of Ireland's biggest racing dynasties and is the son of famous trainer Paddy.
Born: 5 September 1956
Started training: 1988
Base: Closutton, Co Carlow
Major victories: King George VI Chase, Irish Hennessy (four times).
2003-04 wins: 68
2002-03 wins: 32
2001-02 wins: 50
Willie was Irish amateur champion six times in a career as a jockey that included victory in the 1983 Foxhunters (known as the amateurs' Grand National) at Aintree.
He acted as assistant to his father and to Jim Bolger before taking out his own licence for his stables at Bagnalstown on the Carlow/Kilkenny border.
Paddy Mullins trained the legendary Dawn Run to Champion Hurdle and Gold Cup success and his son has also enjoyed Cheltenham Festival success.
Willie has become a specialist in the Festival Bumper, winning the race four times, three of the victories coming in consecutive years.
One of the bumper wins came in 1996 on Wither or Which, which a 40-year-old Mullins both trained and rode.
Another of the victories came courtesy of a horse who became Mullins' biggest stable star - Florida Pearl.
The popular gelding also won the King George VI Chase and a record four Irish Hennessy Gold Cups as well as coming second and third in the Cheltenham Gold Cup.
Willie Mullins Q&A
Favourite horse trained for the National?
Hedgehunter - loves Aintree and jumps effortlessly around the course.
First memory of the National?
Watching Anglo win on the television in 1966.
Best memory at Aintree?
Riding Eliogarty to victory in the 1983 Foxhunters Chase.
If you win how would you celebrate?
We've had plenty of practice - just in the usual Irish manner really!
Favourite film and song?
Sitting on the dock of the bay by Otis Redding.