Nicholas James D'Arcy[1] (born 23 July 1987)[2] is a retired national-record holding butterfly swimmer from Australia.

[8] At the 2007 World Aquatics Championships in Melbourne, Victoria, D'Arcy competed in the 200 m butterfly, where he came 14th in the heats in a time of 1 min 57.88 s, scraping into the semifinals by 0.09 s. He improved his time to 1 min 57.15 s to finish 12th, missing the final by 0.68 s. The 2008 Australian Swimming Championships held in March in Sydney, were used to select the Australian swimming team for the Beijing Olympics.

[13] At the Commonwealth Games, D'Arcy was expected to take home the gold medal in the 200 m butterfly as his fastest time for the year was more than two seconds faster than any of the other entrants, but he failed to qualify for the final after a slow heat.

He pleaded guilty to one charge of recklessly inflicting grievous bodily harm, the victim suffered fractures to his jaw, eye socket, hard palate, cheek bone and nose.

[21] In March 2009, D'Arcy received a jail sentence of 14 months and 12 days, suspended on condition of good behavior.

[26] In December 2011, after Cowley had been awarded $180,000 in damages, D'Arcy declared himself bankrupt,[27] bringing his representation of Australia at the London Olympics in 2012 in jeopardy.

The controversy that followed[30] in Australia was another incident that distracted attention from D'Arcy's swimming achievements and his preparation for the London Olympics.

[31] It has been reported that senior members of the Australian swimming team consider this a precautionary measure designed to prevent any further potential for controversy from these two swimmers at the Olympics.