"Fool #1" is a song written by Kathryn R. Fulton and performed by Brenda Lee. The song reached No.3 on the Billboard Hot 100 and No.38 in the UK (where it was entitled "Fool No.1", because the # symbol was not synonymous with the word 'number' for British audiences) in 1961. The song also reached No.23 in Australia. The song was featured on Lee's 1962 album, Brenda, That's All.

The single's B-Side, "Anybody But Me", reached No.31 on the Billboard Hot 100.

...
Wikipedia