There are 12 players on each Ryder Cup team.
The competition pits a United States team against a Europe team in a series of match-play sessions. The 12 players on each side compete across foursomes, four-ball matches, and singles. On the final day, all 12 members play one singles match, producing 12 singles contests.
Not every player must appear in the first two days. The captain selects lineups for the team matches, and a player can compete in multiple sessions, subject to the event’s format. The captain also leads the team but is not counted among the 12 players.
The number is not universal across the Ryder Cup’s entire history. The original teams had 10 players, and the team size increased to 12 in 1969. The modern 28-match structure dates from 1979, when continental European golfers joined the side previously known as Great Britain and Ireland. Thus, 12 is the standard modern answer.