“Peek-a-Boo” (Hangul: 피카부; RR: Pikabu) is a Korean song recorded by South Korean girl group Red Velvet for their second studio album, Perfect Velvet (2017). The song was released on November 17, 2017 and served as its lead single. It was composed by Moonshine, Ellen Berg Tollbom and Swedish singer-songwriter Cazzi Opeia.
“Peek-a-Boo” was described as an up-tempo pop dance song with trop house elements. The song and the album received generally positive reviews from critics, who praised the group for their transition from their brighter and bubblier image from their last two singles “Rookie” and “Red Flavor” (both released in the same year), to a more mature sound. The song was a commercial success, peaking at #2 on both the Gaon Digital Chart and Billboard’s World Digital Songs chart.
Red Velvet promoted the song on several music programs, including Music Bank, Inkigayo. The Show and Show Champion. The group also held a comeback showcase in November 2017.