The Batman star, who also sought help for alcohol abuse back in 2001, described the treatment as the "first of many steps being taken towards a positive recovery".
It was first rumoured back in January that Ben Affleck was having problems with booze again after he was spotted out and about in LA with Elizabeth Weaver, who's famed for offering a "sober living companionship service" with her company Concierge Nursing Care.
Perhaps one of the main reasons the 44-year-old actor decided to check himself into rehab was for the sake of his three children he has with his estranged wife Jennifer Garner. The two-time Oscar winner opened up back in 2012 about how he knew from his own personal experiences that an alcoholic in the family can have a serious effect on the children. His parents broke up when he was 12-year-old because of his father's own problems with hitting the bottle.
"It was difficult. When one's parent is an alcoholic, it's hard. It was a little scary and trying, but then he got sober when I was twentysomething, and he's been sober ever since," Ben revealed in an interview with The Hollywood Reporter back in 2012.
In his statement released on Facebook last night (14 March), Ben Affleck wrote: "I have completed treatment for alcohol addiction; something I've dealt with in the past and will continue to confront.'
"I want to live life to the fullest and be the best father I can be. I want my kids to know there is no shame in getting help when you need it, and to be a source of strength for anyone out there who needs help but is afraid to take the first step."
Ben Affleck also thanked his estranged actress wife and his friends for standing by him during this difficult period in his life. "I'm lucky to have the love of my family and friends, including my co-parent, Jen, who has supported me and cared for our kids as I've done the work I set out to do."
He first checked himself into rehab back in 2001, a few short years after winning winning an Oscar for 'Good Will Hunting'. He said at the time, "I went to rehab for being 29 and partying too much and not having a lot of boundaries and to clear my head and try to get some idea of who I wanted to be."