The former X Factor judge premiered the Calvin Harris-produced first cut from her upcoming third album A Million Lights on Friday (April 20).
Cole tweeted Cowell in January about her victory in a 'Best Judge' poll, the first public communication since the 'Promise This' star was axed from The X Factor USA last year, after quitting the UK version to take up the new role.
"I heard the new @CherylCole single today," Cowell told 2.1 million followers on Saturday (April 21) night. "I.Love.It. It's going to be a big hit (sic)."
Responding to the praise, Cole tweeted back: "SayMyName Baby *raspberry*lol (sic)."
The music mogul, who hit the headlines last week after revelations about his private life were made in an unauthorised biography, did not comment on Cole's enthusiastic tweets about BBC One's The Voice UK, which is currently battling Britain's Got Talent in the ratings.
Commenting on the "talented" singers, the 28-year-old tweeted as the top 20 were revealed during the Battle Rounds.
> Cheryl Cole 'for autumn arena tour'
Listen to Cheryl Cole's new single 'Call My Name' below: