Twenty nations competed at the 2023 Rugby World Cup.
The tournament was held in France from 8 September to 28 October 2023. The 20 teams were divided into four pools of five, with each side playing four pool matches. The top two teams from each pool advanced to the quarterfinals.
Twelve teams qualified automatically by finishing in the top three of their pools at the 2019 Rugby World Cup. Eight more places were decided through regional qualifying competitions, playoffs and a final repechage tournament. Portugal secured the last place by winning that repechage event in November 2022.
The number is easy to mix up with the 24-team format introduced for the 2027 Rugby World Cup. France 2023 was the final edition using 20 teams. South Africa retained the title by defeating New Zealand 12–11 in the final, becoming the first team to win the Rugby World Cup four times.