| 2021 Slovak Open II | |
|---|---|
| Date | 8–14 November |
| Edition | 23rd |
| Category | ATP Challenger Tour |
| Surface | Hard (Indoor) |
| Location | Bratislava, Slovakia |
| Champions | |
| Singles | |
 Tallon Griekspoor | |
| Doubles | |
 Filip Horanský /  Sergiy Stakhovsky | |
The 2021 Slovak Open II was a professional tennis tournament played on hard courts. It was the 23rd edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Bratislava, Slovakia between 8 and 14 November 2021.