In a press conference in Florida before a small number of journalists Woods said: 'I am deeply sorry for my irresponsible and selfish behaviour. I know I have bitterly disappointed all of you.
'I thought only about myself. I thought I could get away with whatever I wanted to. I felt I was entitled and thanks to money and fame I didn't have to go far to find them. I was wrong, I was foolish. I don't get to play by different rules.'
He also used the press conference to apologise to his fans and sponsors.
At points Woods angrily berated the press for harrassing his family and vehemently refuted speculation that his wife had physically attacked him last November.
He also said he would be returning for further treatment and therapy and said he would not be returning to golf in the immediate future.
He concluded the press conference by saying: 'There are many people in this room and at home who believed in me. Today I want to ask for your help. I ask you to find room in your heart to one day believe in me again.'
There were three wire reporters in the room during the press conference, alongside family members including Woods' mother, whom he hugged after his speech had finished. His wife Elin was not present.
Threepipe co-founder Eddie May said of the press conference: 'Tiger's statement was never going to be massively revealing, given that there were no questions allowed. He did a reasonable, if overly long, job of making an apology, but laid it on a bit thick with all the references to therapy, and suddenly talking about Buddhism seemed a bit unnecessary. It all looked very staged, but it was always going to be.'
He added: 'I don't think this event really changed much or told anyone anything they didn't already know, but at least he's surfaced and made the first step on the road to media recovery. I suspect he'll be back on the golf course pretty soon and the real test will be his first real press conference and how he deals with constant questions in the future.'
Woods has not spoken in public since allegations that he had been having several extra-marital affairs came to light last year. Global media interest was sparked by a mysterious car crash involving Woods, which happened outside his Florida home on 27 November.
He was initially criticised for not addressing the media immediately afterwards and PR experts predicted the media would fill the information vacuum.
Woods avoided appearing in public and instead relied on a series of statements posted on his website. He has taken an indefinite break from golf ever since.
The negative media attention saw Woods dropped by sponsor Accenture, while Gillette scaled back its work with him. PR professionals predicted at the time that more sponsors would follow suit.