See main article: 2011 Medibank International Sydney. Marcos Baghdatis was the defending champion after defeating Richard Gasquet in the 2010 final but had to withdraw from the tournament in 2011.
Gilles Simon won the championships by beating 4th seed Viktor Troicki 7–5, 7–6(7–4) in the final.
The top four seeds receive a bye to the second round.
See main article: 2011 Medibank International Sydney – Men's singles qualifying.