His best-known Billboard Hot 100 hits are: "You Mean Everything To Me" (#17, 1960), "Oh, Carol" (a reference to former girlfriend Carole King) (#9), "Calendar Girl" (#4, 1960), "Happy Birthday Sweet Sixteen" (#6, 1961), "Breaking Up Is Hard to Do" (#1, 1962), "Laughter in the Rain" (#1, 1975), and "Bad Blood" (#1, 1975). Sedaka's voice is in a tenor to alto range.

Sedaka and Greenfield also wrote "Love Will Keep Us Together", a No. 1 hit for The Captain and Tennille and the best selling record of 1975. Sedaka also recorded this song but his version was much less popular than Captain and Tennille's recording of the song, which includes the lyrics "Sedaka is back" in the coda.

Sedaka was born to a Turkish Jewish immigrant to Brooklyn and an Ashkenazi Jewish mother. He began performing on the piano as a youth, and played on a classical music radio station, as well as studying at Juilliard. He also began experimenting with doo wop and rock and roll, playing in an early version of The Tokens. His composition, "Stupid Cupid" was a 1958 success for Connie Francis, and Sedaka was signed to RCA Records as a solo performer. A string of hits followed, ending in 1963.

Sedaka returned to the forefront in 1973, helping ABBA write the English lyrics of the song "Ring Ring" for the Eurovision contest. Later in the 1970s, after he experienced a comeback in both recording and songwriting, he began working in England with Elton John and continued touring for many years after that.

In 1976, Sedaka recorded a new version of "Breaking Up is Hard to Do," a ballad which sounded very different from the original version released in 1962, being a jazz/torch piano centered arrangement. It made #8 on the pop charts; the original made it to #1. The ballad version charted at #1 on the Billboard Adult Contemporary chart.

He was also the writer of the popular song 'Amarillo' a song he wrote for Britain's Tony Christie, it reached the top 40 in the UK twice, in 1971 and 2005 - hitting #1 the second time thanks to an amusing video starring Christie, Peter Kay and many other celebrities. It also reached #1 in Spain and Germany in 1971. Sedaka later recorded the song himself, taking it into the U.S. Hot 100 singles chart. On April 7, 2006, during a concert at the Royal Albert Hall in London, Neil Sedaka was presented with an award from the book 'Guinness World Records: British Hit Singles and Albums' as the writer of the Best-Selling Single of the 21st century for 'Amarillo'.

In 1962, Neil Sedaka married his wife, Leba, and they are still together. They have two children: daughter Dara, a recording artist and vocalist for television and radio commercials, and son Marc, a screenwriter who lives in Los Angeles, California. In 1980, Sedaka had a Top 40 hit with "Should've Never Let You Go," which he recorded with Dara. Marc and his wife, Samantha, are the parents of twin girls, Amanda and Charlotte, who were born in 2003 and are Neil Sedaka's first grandchildren. Marc and Samantha also gave birth to a son, Ethan, in 2005. Neil Sedaka hopes that all of his grandchildren will learn to play the piano.

In 1985, Sedaka composed songs for the anime series Mobile Suit Zeta Gundam. These included the two opening themes "Zeta - Toki wo Koete" and "Mizu no Hoshi e Ai wo Komete". As well as the ending theme "Hoshizora no Believe". Due to rights issues, the production company Sunrise, Inc. could not come to an agreement for the use of the songs in North America. Controversially, the songs were then replaced with other music for the North American DVD release.

In 2006, Sedaka continues to perform regularly. He now has a star on the Hollywood Walk of Fame and a petition is under way for Sedaka to be inducted into the Rock and Roll Hall of Fame.