Karen Lee Orzolek is a South Korean-born American singer, musician, and songwriter. She is the lead vocalist of the indie rock band Yeah Yeah Yeahs.

Yeah Yeah Yeahs are an American indie rock band formed in New York City in 2000. The group is composed of vocalist and pianist Karen O, guitarist and keyboardist Nick Zinner, and drummer Brian Chase. They are complemented in live performances by second guitarist David Pajo, who joined as a touring member in 2009 and replaced Imaad Wasif, who had previously held the role. According to a 2004 interview that aired during their appearance on ABC's Live from Central Park SummerStage series, the band's name was taken from modern New York City vernacular.