The 2025 Yokohama Keio Challenger was a professional tennis tournament played on hardcourts. It was the 18th (men's) and 8th (women's) editions of the tournament and part of the 2025 ATP Challenger Tour and the 2025 ITF Women's World Tennis Tour. It took place in Yokohama, Japan between 17 and 30 November 2025.
The following players received wildcards into the singles main draw:
The following player received entry into the singles main draw through the Junior Accelerator programme:
The following players received entry from the qualifying draw:
The following players received wildcards into the singles main draw:
The following player received entry into the singles main draw using a special ranking:
The following players received entry from the qualifying draw: