Alexandre Liess (born June 20, 1991) is a Swiss swimmer, who specialized in freestyle and butterfly events.

[1][2] 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.

[1][3] Liess qualified for the men's 200 m butterfly at the 2012 Summer Olympics in London, by breaking a Swiss record and eclipsing the FINA B-cut off time of 1:58.13 at the European Championships in Debrecen, Hungary.

[4][5] He challenged seven other swimmers in the second heat, including former semifinalist Hsu Chi-chieh of the Chinese Taipei.