"Knock on Wood" is a 1966 hit song written by Eddie Floyd and Steve Cropper and originally performed by Floyd. His recording peaked at number 28 on the Hot 100 and spent one week at number 1 on the Soul Singles chart.
The most successful version of "Knock on Wood" was recorded by Amii Stewart, who made a disco version of the song in 1979. It was Stewart's debut single and reached number one in the U.S. charts in April 1979; it also made it to the soul singles and disco charts, becoming the best-known version of the song. This recording was co-produced by Simon May. It reached the Top 10 twice in the UK, first in 1979 (peaking at number 6) and again in a remixed version in 1985 (peaking at number 7). Stewart's version was also featured in the 1998 film The Last Days of Disco. It became a platinum record.