| Season: | 2021–22 |
| Nextseason: | 2022–23 |
The 2021–22 3. Liga is the 29th season of the third-tier football league of Slovakia since its establishment in 1993. The league is composed of 66 teams divided into three groups of 16 teams and one group (Západ) composed of 18 teams. Teams are divided into four divisions: 3. liga Bratislava, 3. liga Západ (West), 3. liga Stred (Central), 3. liga Východ (Eastern), according to geographical separation.
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