"Walking on Sunshine" is a song written by Kimberley Rew for Katrina and the Waves' 1983 eponymous debut full-length album. A rerecorded version was released on the band's 1985 self-titled album as the album's second single (see 1985 in music) and reached No. 4 in Australia, No. 9 in the United States, and No. 8 in the United Kingdom. It is the Waves' first U.S. top 40 hit, and their biggest success in the UK until "Love Shine a Light" (1997). Conceived of as a ballad, Katrina decided the better part of valor was to belt the song out.
2010 was the 25th anniversary of the release of "Walking on Sunshine" and a series of back-catalog re-releases and a re-recorded version of the track are being released. A free download of one of the tracks from Kimberley Rew's solo album 'Bible of Bop' was given away in March 2010 from the band's website. 
Royalties from airplay and advertisements of "Walking on Sunshine" has been extremely high. Katrina and the Waves kept the publishing rights and the royalties that typically go to the songwriter have been divided among the band members, though Katrina Leskanich was fired from the band in 1998. Estimates are that the song has earned $1 million per year for the ten years ending in 2010. According to a former employee of EMI, "Walking on Sunshinewas the crown jewel in EMI's catalog," and that it was one of EMI's biggest earners from advertisers.
The music video depicts the band performing live at a London concert. Katrina herself is either with or not with them, but either dancing in her apartment, or walking through Hyde Park on a cloudy day, past an English prison, the Tower Bridge, a cliff and Old St. Paul's. She catches up with the others and feeds ducks (one of them eats the leftovers, referring to the Waves). Katrina returns home and cleans her face using cotton.