This list shows the appearances of all participants in the men's tennis ATP World Tour Finals singles since their inception as the Pepsi-Cola Masters in 1970. The current sponsor is Barclays, and they are currently held on hard courts indoors in the O2 Arena in London.
Before 1982 and since 1986, the tournament pits the top eight players on the ATP tour against each other in two groups in which they play three round-robin matches. Two players from each group advance to the semifinals, and the winners to the finals.
From 1982-1985, there were additional participants.
Participants are listed in order of number of appearances, number of wins, and first appearance. When there are more than eight players listed for any year since 1986, it is usually due to withdrawal because of injury. When a player withdraws early in the tournament, his place is filled by the next-highest qualifier.
W = winner; F = runner-up; SF = lost in semi-finals (1972–present); QF = lost in quarter-finals (1982–85); R16 = lost in 1st round/Round of 16 (1982–85); RR = lost in Round Robin group stage (1972–81, '86–present); 3rd-7th = standings in the RR group (1970–71); A = Alternate (did not play from the beginning; 1996–present); A' = Alternate (played from the beginning = original player withdrew before the tournament); W = withdrew during the tournament (1996–present)