Speaking for the first time in public since accusations about his private life emerged last November, the 34-year-old admitted he had been unfaithful to wife Elin Nordegren and apologised to those he had let down.
"I know I have bitterly disappointed all of you. I have made you question who I am and how I could have done the things I did. I'm embarrassed that I have put you in this position," he said in the live TV address from the TPC Sawgrass golf course.
Talking in front of a select audience of journalists, friends, colleagues and family, including his mother, Tiger acknowledged that rebuilding his and Elin's relationship would be a long journey.
"My real apology to her will not come in the form of words. It will come in my behaviour over time," he said.
"We have a lot to discuss. However, what we say to each other will remain between the two of us."
The sportsman also said sorry to the young fans around the world he had let down.
"Parents used to point at me as a role model for their kids. I owe all those families a special apology. I want to say to them that I am truly sorry."
Dressed in an unbuttoned blue shirt and dark suit, he said he had been attending in-patient therapy for 45 days to help him with his problems and was drawing strength from his Buddhist faith.
"I need to regain my balance and be centred, so I can save the things that are most important to me: My marriage and my children."
On the subject of his return to golf, he said he did not know when it would be, but didn't rule out a comeback "this year".
After the 13-minute address, a visibly emotional Tiger embraced his mum and other guests.