Billy Cook grew up in Hornsby, New South Wales. He became interested in horses while delivering meat by cart for his father who was a butcher.
Billy Cook was well known for his good judgment of pace and for his balance. He won many feature races including 2 Melbourne Cups and he was also successful overseas. Billy Cook won several Jockey Premierships.
Billy Cook retired in 1959. He passed his talent on to his son Peter who also won two Melbourne Cups.

Some Achievements:

- rode 2,300 winners
- winner of 2 Melbourne Cups
- winner of 1 Caulfield Cup
- finishing runner-up to Sir Gordon Richards, England
- winner of 6 Sydney Jockey Premierships
- runner-up a further ten times
- winner of 1 Bombay Jockey Premiership, India

Some of the horses Cook rode:

- Skipton
- Rainbird
- Amounis