Rex Features
According to USA Today, the former American Idol winner joins an impressive list of performers who've sung the national anthem at the big game, including Billy Joel, Diana Ross, Neil Diamond, Whitney Houston and Harry Connick Jr.
Garth Brooks, Natalie Cole, Vanessa Williams, Luther Vandross, Cher, Faith Hill, Mariah Carey, Dixie Chicks, Beyoncé and fellow Idol alum Jennifer Hudson have also performed the song at the sporting event.
Since leaving the singing competition, Underwood has sold more albums in the US than any other Idol champion.
She follows a trend of past Idol victors who have sung at this year's play-off football games. Recently, Kris Allen performed at the NFC Championship and Jordin Sparks did the same at the final AFC game.
