Esquire credits Williams with "injecting dressed-up luxury into hip-hop style and thereby influencing a new generation of guys to consider more than just a pair of baggy jeans a reflection of their youthful vitality."
Williams, 32, tells the magazine: "It's never about whether I'm the best-dressed guy in the room. I never go, 'Oh, I'm killin' 'em tonight!' Instead it's about comfort and the flow."
Andre 3000, ranked No. 1 last year, dropped to No. 5.
Other best-dressed men include Jake Gyllenhaal, Kanye West, Jude Law, George Clooney, Matt Lauer, Josh Lucas, Alex Kapranos of Franz Ferdinand, Jay-Z, pro quarterback Tom Brady, Prime Minister Junichiro Koizumi of Japan, U.N. Secretary-General Kofi Annan, Southern rock band My Morning Jacket, Luke Wilson, pro running back Curtis Martin, Paul Bettany, former President Clinton, Chris Martin, pro golfer Adam Scott and Donald Trump.
The list, compiled by a panel of fashion experts and Esquire editors, will be in the magazine's September issue.