The ITF claims a doping test administered to Hingis last year during Wimbledon returned positive for cocaine. Hingis, 27, revealed the test result on Nov. 1 and announced her retirement from competitive tennis.
"I find this accusation so horrendous, so monstrous, that I have decided to confront it head-on by talking to the press," Hingis said at the time.
"I am frustrated and angry. I believe that I am absolutely 100 percent innocent."
The ITF suspension was retroactive to Oct. 1, 2007. The ITF also disqualified Hingis' results from Wimbledon -- she was eliminated in the third round -- and the other events she played afterward. She must also repay the prize money from those events, a sum of $129,481.
Hingis, who was ranked 19th in the world when she retired, has three weeks to appeal the ruling.
She also retired in 2002 because of a series of injuries but returned to the tour in 2006. Since then she won three tournaments, running her career total to 43 championships, including five Grand Slam titles.