The 2021 Sun Bowl was a college football bowl game played on December 31, 2021, with kickoff at 12:00 p.m. EST (10:00 a.m. local MST) and televised on CBS.^[2] It was the 88th edition^[3] of the Sun Bowl (87th playing, as the 2020 edition was cancelled due to the COVID-19 pandemic), and was one of the 2021–22 bowl games concluding the 2021 FBS football season. Sponsored by Kellogg's Frosted Flakes breakfast cereal, the game was officially known as the Tony the Tiger Sun Bowl, after its mascot, Tony the Tiger.

On December 26, the Miami Hurricanes announced that they would not be able to play in the game, due to COVID-19 issues; organizers stated that they would try to secure a replacement team to face the Washington State Cougars.^[4]

On December 27, the Central Michigan Chippewas were named as the Sun Bowl replacement team.^[5] The Chippewas had originally been scheduled to face the Boise State Broncos in the Arizona Bowl, until Boise State withdrew from that bowl due to COVID-19 issues.^[6]

The bowl has tie-ins with the Atlantic Coast Conference (ACC) and the Pac-12 Conference. The originally planned matchup featured teams from those conferences. The withdrawal of the Miami Hurricanes, an ACC team, led to Central Michigan, a team from the Mid-American Conference (MAC), being selected to face Washington State of the Pac-12. This was the first time Central Michigan and Washington State played each other.^[7]

The bowl's attendance was the lowest for a Sun Bowl since the 1982 edition.