| Season: | 2021–22 |
| Nextseason: | 2022–23 |
The 2021–22 3. Liga (Slovakia) season was the 29th edition of the third tier football]] competition since its establishment in 1993. 66 teams contested being divided into three geographic groups of 16 teams: 3. liga Bratislava, 3. liga Západ (West), 3. liga Stred (Central), 3. liga Východ (Eastern); except group (Západ) composed of 18 teams.
The following teams have changed division since the 2020–21 season:
Relegated from 2. liga
Promoted from 4. liga
Promoted to 2. liga
Relegated to 4. liga
Relegated to 5. liga