The two UK artists linked up for the highly anticipated track "Sweet Nothing."
"You took my heart/and you held it in your love/with a word all my love came rushing out/and every whisper it's worse/emptied out by a single word," sings Florence.
"Sweet Nothing" is off Calvin's forthcoming new project, 18 Months, which features Kelis, Ellie Goulding, Florence Welch, Ne-Yo, Tinie Tempah and more.
Calvin will also be DJing at Jay-Z's "Made In America" Festival on September 1-2.
Take a listen to Calvin Harris and Florence Welch's new collaboration below!