"All at Once" is a song written by Michael Masser and Jeffrey Osborne and recorded by Whitney Houston. It was released as a single in Japan and several European countries in 1985–1986. While it did not receive an official single release in the United States, the song did receive significant radio airplay there.
It became the first hit for Whitney Houston in the Netherlands in April 1985.
The song is a heartbreak ballad about a lover who leaves without warning and the damage it does. Houston performed the song at the 1987 American Music Awards.