The 2023 ATP Finals (also known as the 2023 Nitto ATP Finals for Nitto sponsorship) was a men's tennis year-end tournament played on indoor hard courts at the Pala Alpitour in Turin, Italy, from 12 to 19 November 2023. It was the season-ending event for the highest-ranked singles players and doubles teams on the 2023 ATP Tour.

This is the 54th edition of the tournament (49th in doubles), and the third time Turin hosted the ATP Tour year-end championships.

The 2023 ATP Finals rewarded the following points and prize money, per victory

The ATP Finals group stage has a round-robin format, with eight players/teams divided into two groups of four and each player/team in a group playing the other three in the group. The eight seeds were determined by the Pepperstone ATP rankings and ATP Doubles Team Rankings on the Monday after the last ATP Tour tournament of the calendar year. All singles matches, including the final, were best of three sets with tie-breaks in each set including the third. All doubles matches were two sets (no ad) and a Match Tie-break.

In deciding placement within a group, the following criteria were used, in order:

If after criterion 4 there was one superior/inferior player and the other two were tied, the head-to-head result was used to sort these two players. Criteria 5-6 were thus used only in case three players were all tied after the evaluation of criteria 1-4.

The top two of each group advanced to semifinals, with the winner of each group playing the runner-up of the other group. The winners of the semifinals then played for the title.

Eight players compete at the tournament, with two named alternates. Players receive places in the following order of precedence: