"Bad Girlfriend" is a song by Canadian rock band Theory of a Deadman and is the second single from their third studio album Scars & Souvenirs (2008). The track's lyrics describe the circumstances of when lead singer and guitarist Tyler Connolly met his now ex-wife in a bar in Vancouver. The band collectively composed the song which was produced by Howard Benson. It peaked at number 42 on the Billboard Canadian Hot 100 chart and number 75 on the Billboard Hot 100, and was their first single to reach number one on the Billboard Mainstream Rock chart, making it the band's most successful release in the United States at the time.