The Southern Districts Tennis Association junior summer competition season for 2020/21 consisted of 14 rounds with 165 teams competing each week.
Tennis SA and Southern Districts Tennis Association would like to thank the clubs and junior coordinators for their hard work and dedication to the sport and would like to formally congratulate the following winners:
Junior Competition
| Boys | |
| Premier League | Happy Valley |
| Division 1 | Morphett Vale |
| Division 2 | Happy Valley |
| Division 3 | Kingswood |
| Division 4 | Denman |
| Division 5 | Noarlunga |
| Division 6 | Kingswood |
| Division 7 | Colonel Light West |
| Division 8 | McLaren Vale |
| Division 9 | Blackwood |
| Girls | |
| Premier League | Peake Gardens Riverside |
| Division 1 | Flagstaff Hill |
| Division 2 | Kingswood |
| Division 3 | Colonel Light West |
| Division 4 | Blackwood |
| Division 5 | Reade Park |
Green Ball Competition
| Boys | |
| Division 1 | Denman |
| Division 2 | Hope Ward |
| Girls | |
| Division 1 | Hope Ward |
| Mixed | |
| Division 1 | O'Halloran Hill |