Alexandre Liess (born June 20, 1991) is a Swiss swimmer, who specialized in freestyle and butterfly events.
He is a 10-time Swiss swimming champion, and currently holds age group national records in the 200 m butterfly.
Liess is a member of SSG Saar Max Ritter in Germany, under his Russian-born coach Gennadi Touretski, who is best known for training multiple Olympic medalists Alexander Popov and Michael Klim in the late 1990s.Liess qualified for the men's 200 m butterfly at the 2012 Summer Olympics in London, by breaking a Swiss record and eclipsing a FINA B-cut of 1:58.13 from the European Championships in Debrecen, Hungary.
He challenged seven other swimmers on the second heat, including former semifinalist Hsu Chi-chieh of the Chinese Taipei.
Liess rounded out the field to last place by 0.16 of a second behind Canada's David Sharpe, outside his record time of 2:00.13.
Liess failed to advance into the semifinals, as he placed thirty-third overall in the preliminaries.