The All-Ireland Senior B Football Championship was a second tier Gaelic football championship competition organised by the Gaelic Athletic Association (GAA).
Counties who were typically defeated in the early rounds of their provincial championships could enter the competition, which was first contested in 1990 when Leitrim became the inaugural winners.
Designed to improve the standard of football in the so-called "weaker" counties, the competition was played for the last time in 2000, as a result of the introduction of the All-Ireland Qualifiers for the 2001 football championship. The qualifier system gave each defeated county a second chance via the "back-door", after losing in the provincial championships.
Format
The championship was played on a straight knockout basis, typically starting in October each year alongside the National League fixtures, and concluding in November or December.