The former N*Sync star said he was not “smart or savvy” enough to sign up for an account on the social networking site.
“I don’t get a lot of free time and when I do I probably most likely want to be golfing or snowboarding,” he added.
Timberlake, who plays Napster supremo Sean Parker in The Social Network, said that as a musician he had mixed feelings about file sharing.
“I connected with the idea of it, because it speaks to my generation, but at the same time I think I had a lot of friends – I still have a lot of friends – who are songwriters,” he said.
“It’s a complicated conversation to explain to someone who might be downloading music in that fashion that these people – that’s their bread and butter, so to speak. That’s the only way they’re able to pay their bills.”