The actor said he began drinking too much while filming "Harry Potter and the Half Blood Prince," the sixth movie in the Harry Potter series, in 2009.
"I became so reliant on (alcohol) to enjoy stuff. There were a few years there when I was just so enamored with the idea of living some sort of famous person's lifestyle that really isn't suited to me," said Radcliffe.
The 21-year-old said he decided to cut out alcohol altogether, instead of just cutting down.
"As much as I would love to be a person that goes to parties and has a couple of drinks and has a nice time - that doesn't work for me. I do that very unsuccessfully," he said.
The actor said he would rather "sit at home and read or go out to dinner with someone, or talk to someone I love, or talk to somebody that makes me laugh."
Radcliffe was speaking to GQ magazine in an interview released Monday.
Radcliffe shot to fame aged 11 after he was cast as Harry Potter for the movie adaptations of J.K. Rowling's popular books about a teenage wizard.
The last movie in the series "Harry Potter And The Deathly Hallows: Part II" premieres on Thursday.
The Associated Press contributed to this report.