2020 All-Ireland Senior Football Championship

The 2020 All-Ireland Senior Football Championship (SFC) was the 133rd edition of the Gaelic Athletic Association's premier inter-county Gaelic football tournament since its establishment in 1887.

The public health measures introduced to combat the COVID-19 pandemic resulted in the competition being delayed. On 17 March, the GAA confirmed that the opening fixture – due to have taken place at Gaelic Park in The Bronx on 3 May – had been postponed. In June, the GAA announced that the 2020 championship would be straight knock-out, the first straight-knockout since 2000.

Thirty teams took part – thirty of the thirty-two counties of Ireland. New York, initially scheduled to host Galway decided on 26 June not reschedule the match, and were unable to participate due to travel restrictions resulting from the COVID-19 pandemic. London, initially scheduled to host Roscommon at Ruislip at the beginning of May, were also eliminated from the 2020 All-Ireland SFC after a meeting of the GAA's Ard Chomhairle on 12 September 2020. Sligo later withdrew due to a COVID-19 outbreak from 3 November.

London were initially scheduled to host Roscommon at Ruislip at the beginning of May, before all GAA activity was postponed due to the COVID-19 pandemic. Roscommon were then set to play their rescheduled Connacht football quarter-final on the weekend of 31 October, with the winner facing Mayo or Leitrim the following weekend. Roscommon advanced directly into the semi-final.

The Galway v Sligo Connacht SFC semi-final was not played as Sligo was overcome by the COVID-19 virus and did not have anyone left to field a team. Thus Galway's first match was the Connacht SFC final. This also left the Connacht SFC with only four teams instead of the usual seven. This previously only happened during the period when all Connacht SFC finals were between Galway and Mayo (1933–1940) again in 1965 the match was rescheduled for the 2023 season.

Both the London and New York games were rescheduled for the 2025 All-Ireland Senior Football Championship.

It emerged that, in order for London's quarter-final to have taken place, their entire panel and backroom team would have had to self-isolate in Ireland for two weeks prior to the match. Kilkenny, as in previous years, did not enter.

In 2020 the GAA planned to introduce the Tailteann Cup, a competition for Division 3 and 4 National Football League teams who did not qualify for their provincial finals or achieve promotion to Division 2 of the league. The Tailteann Cup was cancelled as a result of the impact of the COVID-19 pandemic on Gaelic games and was rescheduled for introduction in 2021, when its introduction was again postponed.

Dublin, the defending champion, completed an unprecedented six-in-a-row.