"I Kissed a Girl" is the debut single by American singer Katy Perry. It was released on April 28, 2008, by Capitol Records as the lead single from her second studio album, One of the Boys (2008). Perry co-wrote the song with Max Martin, Cathy Dennis, and its producer Dr. Luke, with additional production from Benny Blanco. The track was recorded at Dr. Luke's Studios and Legacy Recordings, both based in New York City, New York, and Conway Recording Studios, based in Hollywood, Los Angeles. "I Kissed a Girl" is a pop rock, electropop, bubblegum pop, club, and disco record with elements of glam rock and new wave music. Perry stated its lyrics are "about the magical beauty of a woman". The song sparked controversy for its handling of bi-curious themes, but in retrospect has been credited with increasing LGBTQ awareness in pop music.
"I Kissed a Girl" became a massive commercial success worldwide in 2008. The song topped the Billboard Hot 100 chart for 7 consecutive weeks, becoming the 1,000th number-one song of the rock era. The single has sold 4.8 million units in the US alone. "I Kissed a Girl" is one of eight songs by Perry to sell over 4 million digital copies in the US, the others being "Hot n Cold", "California Gurls", "Teenage Dream", "Firework", "E.T.", "Dark Horse" and "Roar". Outside of the United States, "I Kissed a Girl" topped charts in 20 countries including Australia, Austria, Belgium, Canada, the Czech Republic, Denmark, Germany, Hungary, Ireland, Italy, New Zealand, Norway, Sweden, Switzerland, and the United Kingdom. It was the best-selling song of 2008 in Finland. The song has sold 8 million copies worldwide and received multi-platinum certifications in Australia, Canada, Denmark, the United Kingdom, and the United States.