"Suddenly" is a song from the soundtrack album Xanadu, and is the love theme from the 1980 film of the same name. The song is performed as a duet between Olivia Newton-John and Cliff Richard. It was written by John Farrar who also produced the record. It was released on Jet Records and reached No. 15 in the UK charts in October 1980 and reached No. 20 in the US. The video shows them in a penthouse singing the song to each other.
The song was covered by Filipino singers Sam Milby and Toni Gonzaga on their gold album Love Duets, released February 20, 2009, also released as a single.