The phrase "girl power" is used as a term of female empowerment, independence, and self-sureness. Girl power expressed a cultural phenomenon of the 1990s and early 2000s.
One of the earliest uses of the phrase "Girl Power" was in 1987 by a London-based 'capella' all-girl group called 'Mint Juleps' in a song entitled 'Girl to the Power of 6'.
The phrase "Girl Power" was later used as the title of a 1991 feminist zine by the Olympia, WA/Washington DC-based punk band Bikini Kill, which singer Kathleen Hanna has said was inspired by the "black power" movement/term. The term became popular in the early and mid 90s punk culture. Rolling Stone wrote about the zine and agenda associated with the slogan, "In their feminist fanzine Bikini Kill they articulated an agenda for young women in and outside of music; the band put those ideas to practice. (Ironically, the zine first coined the "girl power" slogan, later co-opted by England's bubblegum pop band the Spice Girls.) Bikini Kill earned a reputation in the punk underground for confronting certain standards of that genre; for example, asking people to slam at the side of the stage, so that women would not get pushed out of the front, and inviting women to take the mike and talk about sexual abuse."
The phrase is sometimes spelled as "grrrl power", initially associated with Riot Grrrl.
"Girl power" was later utilized by a number of bands during the early 1990s, such as the Welsh indie band Helen Love and the Plumstead pop-punk duo Shampoo, who released an album and single titled Girl Power in 1995.
The phrase entered the mainstream, however, during the mid-1990s with the British pop quintet Spice Girls. Professor Susan Hopkins, in her 2002 text, Girl Heroes: The New Force in Popular Culture, suggested a correlation between "girl power", Spice Girls and female action heroes at the end of the 20th century. The Spice Girls credited former Prime Minister Margaret Thatcher, a leading conservative, as the pioneer of their ideology of girl power.