The Church of Scientology has many famous (and infamous) members, Tom Cruise, John Travolta, Kirstie Alley, and Juliette Lewis among them. Beck has long been considered a member as well; he admitted to it in a June 2005 interview with the Irish Sunday Tribune:
"Yeah, I'm a Scientologist, " Beck resumes once she has left. "My father has been a Scientologist for about 35 years, so I grew up in and around it and stuff."
An October 2017 article in The Guardian also brings up his church membership:
He’s a Scientologist, something I’ve been forbidden to ask about. (When Beck has spoken about his religion in the past, he’s described it as “something personal”, inherited from his father.)
I think there's a misconception that I am a Scientologist. I'm not a Scientologist. I don't have any connection or affiliation with it. My father has been a Scientologist for a long time, but I've pretty much just focused on my music and my work for most of my life, and tended to do my own thing … I think it's just something people ran with.
Beck's new album, Hyperspace, came out today.