"Why Can't I?" is a song by American pop rock artist Liz Phair. It was released in May 2003 as the lead single from her self-titled album, Liz Phair. It reached number 32 on the Billboard Hot 100, Phair's highest-charting single to date, and only top 40 single. The single was certified gold, having sold 500,000 copies. The song is featured on the 13 Going on 30 Soundtrack.
Chuck Taylor of Billboard called the song a "melodic adult pop/rocker" and a "knock-out, stand-out, break-out record that adult top 40 should take right home." Matt LeMay of Pitchfork said that with the "cookie-cutter rock/pop background" it could easily pass for Michelle Branch. Mary Huhn of the New York Post called the song "a breathless romantic confection, and very un-Phair-like". Mim Udovitch of Slate called the song an "almost parodically basic power ballad" but stated that the chorus is "hooky". Adrien Begrand of PopMatters called the song a "note-for-note retread" of "Complicated" by Avril Lavigne.