The 2023 Koblenz Open was a professional tennis tournament played on indoor hard courts. It was the fifth edition of the tournament which was part of the 2023 ATP Challenger Tour. It took place in Koblenz, Germany from 30 January to 5 February 2023.
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:
