If You Don't Know Me by Now" is a song written by Kenny Gamble and Leon Huff, and recorded by the Philadelphia soul musical group Harold Melvin & the Blue Notes. It became their first hit after being released as a single in September 1972, topping the US R&B chart and peaking at number 3 on the US Billboard Hot 100.
"If You Don't Know Me by Now" was originally written for Labelle (a trio led by Patti LaBelle) but they never recorded it. Much like the issue with "I Miss You" and The Dells passing on it, the song's composers Kenny Gamble and Leon Huff gave it to Harold Melvin & the Blue Notes, which featured Teddy Pendergrass as lead vocalist. In addition to the single release, the track was included on their debut album I Miss You.
Patti LaBelle later made the song as part of her concert repertoire in 1982; a live version appears on her 1985 album, Patti.
"If You Don't Know Me by Now" has since been covered by a number of other artists, most notably the English pop and soul band Simply Red, who took their version to number one on the Billboard Hot 100 in 1989.
The song was chosen as one of the "Songs of the Century" by the RIAA
Simply Red have over a billion hits on YouTube, have sold over 60 million albums worldwide, 5 going to number one in the UK. Their 1991 classic Stars was the best-selling album for two years running in Britain and Europe. They have had two US Billboard chart toppers with classic singles Holding Back The Years and If You Donít Know Me By Now. Every Simply Red studio album has been a UK top ten (with previous release Big Love reaching number 4 in 2015). Hucknall has been the songwriter and bandleader since the beginning in 1985.