The 2025 Nonthaburi Challenger III was a professional tennis tournament played on hard courts.

It was the 13th edition of the tournament which was part of the 2025 ATP Challenger Tour.

It took place in Nonthaburi, Thailand from 13 to 19 January 2025.

[1] The following players received wildcards into the singles main draw: The following players received entry into the singles main draw as alternates: The following players received entry from the qualifying draw: