'I didn't drink until I was 25, and I never drank every day, but when I did, it was bad,' News of the World quoted him, as saying.
'It would be a couple of days that just wouldn't work out for me, waking up with a hangover. I used to drink like a 14-year-old kid. Oh Jaysus, I did the most embarrassing things.
'But about a year and a half ago, I woke up and asked myself where I wanted to go. I decided I wanted to be a really successful movie actor. So, I just gave up partying completely,' he added.
However, he said that he knows he has to get sober if he wants to keep his blossoming career on course.
'Drink doesn't fit into the groove of where I'm going. I want to do really good things with my life and drinking is not synonymous with that,' he said.
The 'Bend It Like Beckham' star admitted that when he gets hammered he's tormented by flashbacks to his tough childhood, during which he endured spells in care when his mother could not cope.
Rhys Meyers has checked himself into rehab clinics twice this year.
The actor has become a household name thanks to his portrayal of a highly sexed Henry VIII in 'The Tudors', the Emmy award-winning BBC2 mini-series.