The 2023 Japan Open Tennis Championships (also known as the Kinoshita Group Japan Open for sponsorship reasons) was a men's tennis tournament played on outdoor hard courts.

It was the 48th edition of the Japan Open, and was part of the ATP Tour 500 series of the 2023 ATP Tour.

It was held at the Ariake Coliseum in Tokyo, Japan, from 16 to 22 October 2023.

[1] The following players received wildcards into the singles main draw: The following players received entry from the qualifying draw: The following pairs received wildcards into the doubles main draw: The following pair received entry from the qualifying draw: The following pairs received entry as lucky losers: