"If You Leave Me Now" is the title of a popular hit ballad by the American rock group Chicago, from their album Chicago X. It was written and sung by bass guitar player Peter Cetera and released as a single in July 1976.
The single topped the US charts on October 23, 1976 and stayed there for two weeks, making it the first number one hit for the group. It also reached the number one spot in the UK, maintaining the position for three weeks. It was popular in multiple radio formats, and at one point during its peak listeners could hear it being played simultaneously on four different New York City radio stations.
"If You Leave Me Now" was also Chicago's biggest hit worldwide, after topping the charts in other countries such as Britain and Australia. It went on to win Grammy Awards for Best Arrangement Accompanying Vocalist(s) and Best Pop Vocal Performance by a Duo, Group or Chorus.