| Date: | 20–26 January |
| Edition: | 14th |
| Surface: | Hard |
| Location: | Rennes, France |
| Champs: |  Arthur Rinderknech |
| Champd: | Antonio Šančić /  Tristan-Samuel Weissborn |
The 2020 Open de Rennes was a professional tennis tournament played on hard courts. It was the fourteenth edition of the tournament and part of the 2020 ATP Challenger Tour. It took place in Rennes, France between 20 and 26 January 2020.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Ukraine | Sergiy Stakhovsky | 152 | 1 | |
| Oscar Otte | 163 | 2 | ||
 Serbia | Danilo Petrović | 166 | 3 | |
 Slovakia | Lukáš Lacko | 178 | 4 | |
| France | Maxime Janvier | 201 | 5 | |
 Russian Federation | Alexey Vatutin | 207 | 6 | |
 Spain | Bernabé Zapata Miralles | 210 | 7 | |
| France | Tristan Lamasine | 214 | 8 | |
| Mats Moraing | 221 | 9 | ||
| France | Constant Lestienne | 224 | 10 | |
| France | Alexandre Müller | 226 | 11 | |
| Spain | Roberto Ortega Olmedo | 238 | 12 | |
| Tobias Kamke | 245 | 13 | ||
| Russian Federation | Pavel Kotov | 247 | 14 | |
 Turkey | Cem İlkel | 264 | 15 | |
| Austria | Lucas Miedler | 276 | 16 |
The following players received wildcards into the singles main draw:
Dan Added Evan Furness Kyrian Jacquet
Jerzy Janowicz Valentin RoyerThe following players received entry into the singles main draw as alternates:
The following players received entry from the qualifying draw:
See main article: 2020 Open de Rennes – Singles.
Arthur Rinderknech def. 
James Ward 7–5, 6–4.See main article: 2020 Open de Rennes – Doubles.
Tristan-Samuel Weissborn def. Teymuraz Gabashvili / Lukáš Lacko 7–5, 6–7(5–7), [10–7].
