"Opa Opa" is a song by Greek singer Notis Sfakianakis, released as a single from his second album Ise Ena Pistoli in 1992. It is a laïko dance song and was written and produced by singer Giorgos Alkaios years earlier, and is one of Sfakianakis' most notable of his early works and the most notable version of the song domestically. The song has been covered by a number of artists, taking it to further success abroad. In 1999, Swedish-Greek duo Antique covered it as their debut single with Eurodance elements, reaching the top ten across Scandinavia. Despina Vandi's English-language cover, however, achieved the most success abroad, reaching the top 20 of several markets in Europe and North America.
Swedish-Greek eurodance duo Antique covered the song and released it in July 1999 as the lead single from their debut album, Mera Me Ti Mera. Their version reached the top ten in Denmark, Norway, Romania, and Sweden.
"Opa Opa" fared well in the charts and was Bonnier Amigo's first international hit release in 2000. It entered the Swedish charts on July 15, 1999 and remained for 16 weeks, peaking at number 5. The song entered the Norwegian charts where it peaked at nine staying charting for eight weeks. "Opa Opa" also charted in Switzerland where it peaked at number 51, charting for five weeks.
With the success of her album Gia (2001) in Greece and neighbouring markets, Vandi embarked on a career abroad with remixes and English versions of her past songs, most notably "Gia", which entered the charts of several countries worldwide. She followed with "Come Along Now", from the album of the same name while "Opa Opa" was used as the second single from both aforementioned album and the international edition of Gia. For its release, the lyrics were rewritten in English and dance-pop elements were added into the Greek arrangement. Vandi's version has achieved the most success abroad, managing to reach the top ten and top twenty in several European markets.
The music video was directed by Kostas Kapetanidis. The video is shot over six scenes, with Vandi changing outfits a total of seven times. The video begins with a flash of Vandi's logo, while she can be faintly seen in a red bikini through translucent glass of a sauna; the same shot was used to create the cover of the single. The video returns to this scene numerous times throughout, sometimes with other females appearing in the shot and sometimes with Vandi and a male. It also features Vandi and friends sitting around and later dancing at a club, and on a boat, while there are a further two scenes of Vandi singing alone in front of a background, one of which she appears on top of a motorcycle. During the climax of the song, Vandi punches through glass with her bare fist.