The 2025 Fairfield Challenger was a professional tennis tournament played on hardcourts. It was the ninth edition of the tournament which was part of the 2025 ATP Challenger Tour. It took place in Fairfield, California, United States between October 6 and October 12, 2025.
The following players received wildcards into the singles main draw:
The following player received entry into the singles main draw using a protected ranking:
The following player received entry into the singles main draw through the Junior Accelerator programme:
The following player received entry into the singles main draw as an alternate:
The following players received entry from the qualifying draw: