ATP Tennis - Thiago Monteiro
- Tournament: N/A
- Round: N/A
- Opponent: N/A
- DOB: 1994-05-31
- Birthplace: Brazil, Brazil
- Height: N/A
- Weight: N/A
- Plays: L
- Current World Rank: 77
- Hard: 9-21
- Clay: 33-37
- Grass: 1-2
| Tournament | Date | Sets | Round | Winner | Loser |
|---|---|---|---|---|---|
| Argentina Open | Mar 3, 2021 | 5-7, 6-3, 6-4 | Second Round | Miomir Kecmanovic | Thiago Monteiro |
| Argentina Open | Mar 1, 2021 | 6-2, 6-3 | First Round | Thiago Monteiro | Roberto Carballes Baena |
| Cordoba Open | Feb 26, 2021 | 6-2, 2-6, 6-3 | Quarter Finals | Juan Manuel Cerundolo | Thiago Monteiro |
| Cordoba Open | Feb 25, 2021 | 6-3, 6-4 | Second Round | Thiago Monteiro | Roberto Carballes Baena |
| Cordoba Open | Feb 23, 2021 | 6-3, 6-3 | First Round | Thiago Monteiro | Joao Menezes |
| Australian Open | Feb 10, 2021 | 6-4, 6-4, 7-6 (10-8) | Second Round | Andrey Rublev | Thiago Monteiro |
| Australian Open | Feb 8, 2021 | 7-6 (8-6), 6-1, 6-2 | First Round | Thiago Monteiro | Andrej Martin |
| Great Ocean Road Open | Feb 5, 2021 | 6-3, 6-4 | Semi Finals | Stefano Travaglia | Thiago Monteiro |
| Great Ocean Road Open | Feb 4, 2021 | 6-4, 6-4 | Quarter Finals | Thiago Monteiro | Jordan Thompson |
| Great Ocean Road Open | Feb 4, 2021 | 7-6 (7-3), 6-3 | Third Round | Thiago Monteiro | Carlos Alcaraz |
