"Happenin' All over Again" is a song written and produced by Stock Aitken & Waterman for Lonnie Gordon's first album If I Have to Stand Alone (1991). It was released as the album's second single in January 1990 and reached #4 on the main UK singles chart The song mixed Stock Aitken & Waterman's Europop sound with the blooming Italo house music which was becoming big in the UK charts at the time. This 1990 version was never released in the USA.

A different version of the song was included on Gordon's 1993 album Bad Mood. This version was released as a U.S. single in 1993 and peaked at #98 on the Billboard Hot 100 chart, and also hit #1 on the U.S. Dance chart.

"Happenin' All Over Again" was written for Lonnie Gordon and not, as has been the rumour for many years, Donna Summer.