David Karasek (born 6 October 1987 in Zurich) is a Swiss swimmer, who specialized in freestyle and individual medley events.

[1][3] Karasek qualified for the men's 200 m individual medley at the 2012 Summer Olympics in London, by breaking a Swiss record and eclipsing a FINA B-cut of 2:01.79 from the national championships in Zurich.

[4][5] He challenged seven other swimmers on the second heat, including Olympic veterans Bradley Ally of Barbados, Martin Liivamägi of Estonia, and Raphaël Stacchiotti of Luxembourg.

He edged out Tunisia's Taki M'rabet to pick up a seventh spot by 0.06 of a second, lowering his own Swiss record to 2:01.35.

[1][3] In February 2013, Karasek said that he is working on a master's degree of finance at the IE Business School in Madrid, Spain.