The 2018 Stockton Challenger was a professional tennis tournament played on outdoor hard courts.

It was the third and fourth editions of the tournament and was part of the 2018 ATP Challenger Tour and the 2018 ITF Women's Circuit.

It took place in Stockton, United States, on 1–7 October 2018.

The following players received wildcards into the singles main draw: The following player received entry into the singles main draw as a special exempt: The following player received entry into the singles main draw as an alternate: The following players received entry from the qualifying draw: The following players received a wildcard into the singles main draw: The following players received entry into the singles main draw using a junior exempt: The following players received entry from the qualifying draw: The following player received entry as a lucky loser: