| Dennis Janssen | |
| Birth Date: | 14 September 1992 |
| Birth Place: | Nijmegen, Netherlands |
| Youthclubs1: | SVO |
| Years1: | 2011–2019 |
| Caps1: | 205 |
| Goals1: | 10 |
| Years2: | 2019–2020 |
| Caps2: | 12 |
| Goals2: | 1 |
| Years3: | 2021–2023 |
| Caps3: | 35 |
| Goals3: | 1 |
| Years4: | 2023– |
| Clubs4: | Achilles '29 |
Dennis Janssen (born 14 September 1992) is a Dutch professional footballer who plays as a defensive midfielder for Achilles '29.