William Hamlyn-Harris (born 14 January 1978 in Port Vila, Vanuatu) is a male javelin thrower from Australia. His personal best is 85.60 metres, achieved in January 2004 in Canberra.
| 2002 | Manchester, United Kingdom | 4th | 79.89 m | ||
| Madrid, Spain | 7th | ||||
| 2003 | Daegu, South Korea | 3rd | 75.50 m | ||
| 2004 | Olympic Games | Athens, Greece | 21st (q) | 77.43 m | |
| 2006 | Melbourne, Australia | 2nd | 79.89 m |