Diamond was born and raised in Brooklyn, attending high school with Barbra Streisand (and singing with her in the school choir). He learned to play guitar after receiving one as a gift on his 16th birthday.

He spent his early career as a writer in the Brill Building, and had an early success writing the song "I'm a Believer" for The Monkees.

Neil married school teacher Jaye Posner and they had two children, Marjorie and Elyn. They eventually divorced.

He signed a deal with Bang! Records, and had a string of singles as the primary performer, including "Kentucky Woman," "Cherry, Cherry," and "Solitary Man." Neil's Bang recordings were produced by legendary Brill Building songwriters Jeff Barry and Ellie Greenwich, both of whom can be heard singing backgrounds on many of the tracks.

He moved to Los Angeles, California, in 1970, and signed a deal with MCA Records (then called Uni Records). His sound mellowed, with such songs as "Cracklin' Rosie", "Sweet Caroline" and "Song Sung Blue". "Sweet Caroline" has since become a rallying cry of Red Sox Nation, however unlikely this may seem. Neil married Marcia Murphey, whom he had met while doing a television appearance. They had two sons, Jesse Michael Diamond born in 1970 and Micah Joseph Diamond, born February 14, 1978. Neil and Marcia divorced in 1995.

In 1972, Diamond played 10 sold out concerts at The Greek Theatre in Los Angeles. The performance on Thursday August the 24th was recorded and released as the live double album "Hot August Night". This album demonstrates Diamond's skills as a performer and showman, as he reinvigourated his back catalogue of hits with new energy that make the original studio versions pale by comparison. The album has become a classic, and in Australia, spent a remarkable 29 weeks at number 1 on the music charts.

In 1973, Diamond hopped labels again, this time to Columbia Records, where he recorded the soundtrack to Jonathan Livingston Seagull. In 1974, he released the album Serenade (songs: "Longfellow Serenade", "I've Been This Way Before"). In 1976, he released Beautiful Noise, produced by The Band's Robbie Robertson.

In 1977, he released an album I'm Glad You're Here With Me Tonight, which included the track "You Don't Bring Me Flowers". The song was covered by Barbra Streisand on her album Songbird, which led one disc jockey to combine the two in a virtual duet. The popularity of the virtual duet motivated Diamond and Streisand to record the real thing, which became a very large hit in 1978. A movie version of the song (starring Diamond and Streisand) was planned, but plans fell through when Diamond starred in a remake of the Al Jolson classic The Jazz Singer in 1980, opposite Sir Laurence Olivier and Lucie Arnaz.

Though the movie was not a blockbuster hit at the box office, the soundtrack was a hugely successful album, spawning the singles "America," "Love On The Rocks," and "Hello Again." This would be the apex of his recording career.

In 2000, he was awarded the Sammy Cahn Lifetime Achievement Award by the Songwriters Hall of Fame. In recent years, there has been a resurgence in Diamond's popularity. His songs have become nearly iconic. The 2001 comedy film Saving Silverman (starring Jack Black) plays up this theme. The main characters play in a Neil Diamond cover band, and Diamond made a cameo appearance. During this period, Will Ferrell did a recurring impersonation of Neil on Saturday Night Live.

As of May 2005 he has sold 120 million records worldwide (Source: NY Times), including 48 million records in U.S. (Source: RIAA).

Today, Diamond continues to tour and record. He recently completed and released a new album entitled 12 Songs with producer Rick Rubin. It was released on November 8, 2005 in two editions, one a standard 12-song release, and a special edition with two bonus tracks, including one featuring backing vocals by Brian Wilson. The album debuted at#4 on the Billboard album chart. 12 Songs also ended up being infamous for being one of the last albums to be pressed and released by Sony BMG with the infamous XCP digital rights management software embedded onto the disc (see 2005 Sony CD copy protection controversy).