The 2019 Open Harmonie mutuelle was a professional tennis tournament played on hard courts. It was the sixteenth edition of the tournament which was part of the 2019 ATP Challenger Tour. It took place in Saint-Brieuc, France between 25 and 31 March 2019.
The following players received wildcards into the singles main draw:
The following player received entry into the singles main draw as an alternate:
The following players received entry into the singles main draw using their ITF World Tennis Ranking:
The following players received entry from the qualifying draw:
The following player received entry as a lucky loser: