Duncan Armstrong is a swimmer who has competed for Australia. He competed at the 1988 and 1992 Summer Olympic Games.
At his first Olympics in 1988, Armstrong was not considered a medal favorite in the middle-distance freestyle races and was ranked among the top 50 in the world. He entered the 200 metres freestyle final with a fourth-seeded time from the prelims. Coming from third at the final turn, he launched a late surge to pass Anders Holmertz and Matthew Biondi near the wall for a surprising gold-medal triumph with a new world record of 1:47.25.
Four days later, Armstrong fell behind in the initial length of the men's 400 metres freestyle race until he moved quickly towards the 350-metre turn. He passed almost the rest of the field about the midway of the final lap but could not catch the new world record holder Uwe Daßler of East Germany near the wall to claim only with a silver. He also contributed to the Australians' fourth-place feat in the 4x200 metres freestyle relay, missing the podium by almost a second.
Armstrong missed the cut in his individual events at the Australian trials for Barcelona 1992, failing to defend his title in the 200 metres freestyle. He was selected as a member of the men's 4x200 metres freestyle relay squad but the Australians were disqualified for an early takeoff from Deane Pieters in the final round.
Shortly after his second Olympics, Armstrong retired from competitive swimming.
Olympic Results[]
| Year | Event | Rank |
|---|---|---|
| 1988 | Men's 200m freestyle | 
|
| Men's 400m freestyle | 
| |
| Men's 4x200m freestyle relay | 4th | |
| 1992 | Men's 4x200m freestyle relay | DQ |
1988[]
| Discipline | Round | Time | |
|---|---|---|---|
| 200 metres freestyle | Heats | 1:48.86 | |
| A Final | 1:47.25 | WR | |
| 400 metres freestyle | Heats | 3:50.64 | |
| A Final | 3:47.15 | AR | |
| 4x200 metres freestyle relay | Heats | 7:21.46 (Reserve) |
|
| Final | 7:15.23 (1:47.24 split) |
AR |
1992[]
| Discipline | Round | Time |
|---|---|---|
| 4x200 metres freestyle relay | Heats | 7:22.19 (1:51.53 split) |
| Final | DQ (No time) |