The Cork Under-21 B Football Championship is a Gaelic football competition in County Cork, Ireland for players under the age of 21. Clubs affiliated to Cork board compete to win this championship. All eight of the divisions in Cork organize their own championship. The divisional winners compete against each other to decide the county title. While the divisional competitions have existed since the early 1970s, the county title has only been played since 2010.
| Year | Winner | Opponent |
|---|---|---|
| 2011 | Glenbower Rovers 1-14 | Cill na Marta 0-16 |
| 2010 | Erin's Own 1-08 | Passage 0-09 |