Hebb's parents, William and Ovalla Hebb, were both blind musicians. Hebb and his older brother Harold performed as a song-and-dance duo in Nashville, beginning when Bobby was three and Harold was nine. Hebb performed on a TV show hosted by country music record producer Owen Bradley.
Hebb wrote the song in the 48 hours following a double tragedy on November 22, 1963, the day U.S. President John F. Kennedy was assassinated and Hebb's older brother Harold was stabbed to death outside a Nashville nightclub. Hebb was devastated by both events and many critics say that those events and critically the loss of his older brother inspired the lyrics and tune. According to Hebb, he merely wrote the song as an expression of a preference for a "sunny" disposition over a "lousy" disposition following the murder of his brother.
Events influenced Hebb's songwriting, but his melody, crossing over into R&B (#3 on U.S. R&B chart) and Pop (#2 on U.S. Pop chart), together with the optimistic lyrics, came from the artist's desire to express that one should always "look at the bright side"; a direct quote from the author. Hebb has said about "Sunny": "All my intentions were to think of happier times & pay tribute to my brother – basically looking for a brighter day – because times were at a low. After I wrote it, I thought 'Sunny' just might be a different approach to what Johnny Bragg was talking about in 'Just Walkin' in the Rain.'"
The personnel on the original recording included Joe Shepley, Burt Collins on trumpet, Micky Gravine on trombone, Artie Kaplan and Joe Grimaldi on sax, Artie Butler on piano, Joe Renzetti and Al Gorgoni on guitar, Joe Macho on bass, Al Rogers on drums and George Devens on percussion. the song was originally recorded while the session was in overtime, so many of the studio musicians booked for that date had to leave early for other recording sessions they were booked for.
In America it was released by marimbaphonist Dave Pike on Atlantic Records in 1966 on the Jazz for the Jet Set album, well before Philips released Hebb's 45 version produced by Ross and arranged by Joe Renzetti. This information was made public – as well as sounds from the first two versions of "Sunny" – on the BBC's Songlines program in early 2006.
"Sunny" was recorded at Bell Sound Studios in New York City and released as a single in 1966. It met an immediate success, which resulted in Hebb touring in 1966 with The Beatles.
"Sunny '76" is a disco version of Bobby Hebb's song. Like the original 1966 version, it features Hebb. However, the song was updated with a disco beat so that the music would be played in disco rooms around the world.
The 7" single was released in late 1975 (although it's entitled '76). The b-side featured another Hebb's song called "Proud Soul Heritage".
It was recorded by German euro disco group Boney M., produced by Frank Farian and arranged by Stefan Klinkhammer in a euro disco arrangement. It was taken from their 1976 debut album Take the Heat off Me, following their breakthrough single "Daddy Cool" and was another major hit single that topped the German charts. It has been remixed in 1988 and 1999 (it was a minor hit single early 2000) and was sampled by Boogie Pimps for their 2004 version. While Liz Mitchell sang the original lead vocals on Boney M.'s version, original member Maizie Williams recorded a solo version in 2006. Boney M's version has become the most popular and entered the TOP 10 in many countries, incl. UK, France  and others.
The single was backed by a non-album track "New York City," a reworked version of Farian artist Gilla's 1976 hit single "Tu es!" / "Why Don't You Do It" with an intro borrowed from the album track "Help Help," issued only in some territories instead of "Baby Do You Wanna Bump."
In 2011, the Korean movie Sunny became a box office hit in South Korea. The song of the same name performed by Boney M. was used in the final scene. The song went to number one in the national single chart of South Korea.
The final single from Boney M.'s remix album 20th Century Hits which peaked at #80 in the Swiss charts. The CD single was released with 8 mixes. A "London Mix" was released on the promotional double-12" single.