"After much soul searching, I have decided to take an indefinite break from professional golf," Woods said. "I need to focus my attention on being a better husband, father, and person."
Woods and his wife, Elin, have been married for five years and have a 2-year-old daughter and 10-month-old son.
The announcement came two weeks after a car accident that set in motion a shocking downfall for the world's No. 1 player, which has included sordid allegations of numerous extramarital affairs. One woman even shared a voicemail she said Woods left her two nights before his Nov. 27 accident.
Woods has not been seen in public since the accident. "I am deeply aware of the disappointment and hurt that my infidelity has caused to so many people, most of all my wife and children," Woods said. "I want to say again to everyone that I am profoundly sorry and that I ask forgiveness. It may not be possible to repair the damage I've done, but I want to do my best to try."
The U.S. PGA Tour said it supported the decision by its biggest star.
"His priorities are where they need to be, and we will continue to respect and honor his family's request for privacy," tour commissioner Tim Finchem said in a statement, the tour's first public comment since Woods mentioned his "personal failings" on Dec. 2. "We look forward to Tiger's return to the PGA Tour when he determines the time is right for him."
How long Woods will stay away from golf was unclear.
A year ago, he was out of golf for eight months while recovering from reconstructive knee surgery, and U.S. television ratings dropped 50 percent during his absence.