|Full name||Jonathan Scott Sieben|
|Born||24 August 1966|
|Height||1.76 m (5 ft 9 in)|
|Weight||74 kg (163 lb)|
|College team||University of Alabama|
Hailing from Brisbane, Queensland, Sieben was coached by Laurie Lawrence, and made his debut at the young age of 15 at the 1982 Commonwealth Games in Brisbane, where he captured a bronze in the 200-metre butterfly, as well as gold in the medley relay. Sieben and Lawrence continued their preparation for Los Angeles, but were given little chance. Sieben was known to his friends as The Shrimp, as he stood just 173 cm, in contrast to the dominant swimmer of the time, West Germany's Michael Gross, the world record holder, known as The Albatross with his 200 cm frame and 225 cm wingspan. He also faced the 100-metre butterfly world record holder, the United States' Pablo Morales. Sieben swam in the wake of Gross and Morales in the first 150 metres, before storming home in the last 50 metres to claim the gold medal in a world record time of 1 m 57.04 s, more than four seconds faster than he had ever swum before. He also collected a bronze medal after swimming in the preliminaries of the medley relay. He was named the Young Australian of the Year in 1984.
By the 1988 Summer Olympics in Seoul, Sieben's ability had waned, and the selectors did not choose him for the 200 m butterfly. He finished fourth in the 100-metre butterfly. He continued onto the 1992 Summer Olympics in Barcelona, but failed to reach the final of the 100-metre butterfly individual event. He formed part of Australia's 4x100-metre medley relay team that finished 7th in the final, in a national record time of 3:42.65.
Sieben was inducted into the Sport Australia Hall of Fame in 1985.
- "Sieben, Jonathan Scott". It's an Honour. Retrieved 8 January 2012.
- "Sports Reference profile". Sports Reference. 2014. Retrieved 24 March 2014.
- "Australian of the Year Awards – Jon Sieben". Australia Day Council. Archived from the original on 5 January 2012. Retrieved 8 January 2012.
- "Jon Sieben OAM". Sport Australia Hall of Fame. Retrieved 22 December 2013.
- Andrews, Malcolm (2000). Australia at the Olympic Games. Sydney, New South Wales: ABC Books. p. 397. ISBN 0-7333-0884-8.
- Howell, Max (1986). Aussie Gold. Albion, Queensland: Brooks Waterloo. pp. 257–261. ISBN 0-86440-680-0.
| Men's 200 metre butterfly
world record holder (long course)
3 August 1984 – 29 June 1985