E! also quoted a source as saying the singles were holding hands at one point on New Year’s Eve, though Bullock’s rep said Reynolds was one among a posse of old pals.
"They all had a great time ringing in the New Year as they have in the past ... as nothing more than friends," her rep told People.
Reynolds and Scarlett Johansson filed for divorce last month, citing irreconcilable differences.
Bullock famously kicked her hubby, Jesse James, to the curb last year, amid a cheating a scandal.
The actress, who later this year will star in her first film since splitting from James, is said to be friends with both Reynolds and Johansson.
While Bullock and Reynolds are on record gushing about working together on “The Proposal,” Bullock also famously smooched Johansson during the 2010 MTV Movie Awards, ET notes.