"Girlfriend" is a song by Avril Lavigne. It was the lead single from her third album, "The Best Damn Thing" (2007). It was produced by Lukasz "Dr. Luke" Gottwald. "Girlfriend" became Lavigne's biggest hit in the United States, where it reached number one on the U.S. Hot 100, in Australia, where it topped the chart, and in the United Kingdom, where it reached number two. A remix version featuring singer Lil' Mama was released in June 2007.