The men's Greco-Roman 77 kilograms is a competition featured at the 2021 U23 World Wrestling Championships, and was held in Belgrade, Serbia on 1 and 2 November.
Medalists
| Gold |  Tamás Lévai (HUN)
|
| Silver |  Amin Kavianinejad (IRI)
|
| Bronze |  Albin Olofsson (SWE)
|
 Sergei Stepanov (RUS)
|
Results
- Legend
- F — Won by fall
- WO — Won by walkover
Final
| Final | |||
| Tamás Lévai (HUN)
| 5 | ||
| Amin Kavianinejad (IRI)
| 1 | ||
Top half
| Round of 32 | Round of 16 | Quarterfinals | Semifinals | ||||||||||||
| Tamás Lévai (HUN)
| 5 | ||||||||||||||
| Albin Olofsson (SWE)
| 1 | ||||||||||||||
| Tamás Lévai (HUN)
| 4 | ||||||||||||||
 Daler Rezazade (TJK)
| 0 | ||||||||||||||
 Brandon Calle (COL)
| 0 | ||||||||||||||
| Daler Rezazade (TJK)
| 9 | ||||||||||||||
| Tamás Lévai (HUN)
| 5 | ||||||||||||||
 Dmytro Vasetskyi (UKR)
| 1 | ||||||||||||||
 Edvin Kin (EST)
| 1 | ||||||||||||||
| Dmytro Vasetskyi (UKR)
| 9 | Dmytro Vasetskyi (UKR)
| 7 | ||||||||||||
 Sajan Bhanwal (IND)
| 0 | Dmytro Vasetskyi (UKR)
| 7 | ||||||||||||
 Alexandrin Guțu (MDA)
| 5 |  Gor Grigoryan (ARM)
| 1 | ||||||||||||
| Gor Grigoryan (ARM)
| 11 | Gor Grigoryan (ARM)
| 5 | ||||||||||||
 Gurban Gurbanov (AZE)
| 9 | Gurban Gurbanov (AZE)
| 1 | ||||||||||||
 Zlatomir Emilov (BUL)
| 0 | ||||||||||||||
Bottom half
| Round of 32 | Round of 16 | Quarterfinals | Semifinals | ||||||||||||
 Lamjed Maafi (TUN)
| 5 | ||||||||||||||
 Nikoloz Tchikaidze (GEO)
| 8 | Nikoloz Tchikaidze (GEO)
| 0 | ||||||||||||
| Amin Kavianinejad (IRI)
| 9 | Amin Kavianinejad (IRI)
| 6 | ||||||||||||
 Ardit Ndoj (ALB)
| 0 | Amin Kavianinejad (IRI)
| 10 | ||||||||||||
 Dzmitry Bonka (BLR)
| 8 |  Erkan Ergen (TUR)
| 5 | ||||||||||||
 Jakub Bielesz (CZE)
| 0 | Dzmitry Bonka (BLR)
| 0 | ||||||||||||
| Erkan Ergen (TUR)
| 7 | Erkan Ergen (TUR)
| 2 | ||||||||||||
 Akylbek Talantbekov (KGZ)
| 5 | Amin Kavianinejad (IRI)
| 8 | ||||||||||||
 Foday Kargbo (SLE) | Sergei Stepanov (RUS)
| 0 | |||||||||||||
| Sergei Stepanov (RUS)
| WO | Sergei Stepanov (RUS)
| 7 | ||||||||||||
 Patryk Bednarz (POL)
| 3 | Patryk Bednarz (POL)
| 1 | ||||||||||||
 Per-Anders Kure (NOR)
| 1 | Sergei Stepanov (RUS)
| 8 | ||||||||||||
 Britton Holmes (USA)
| 1 |  Aleksa Ilić (SRB)
| 0 | ||||||||||||
 Dilshod Omongeldiyev (UZB)
| 5 | Dilshod Omongeldiyev (UZB)
| 2 | ||||||||||||
| Aleksa Ilić (SRB)
| 5 | Aleksa Ilić (SRB)
| 6 | ||||||||||||
 Azat Sadykov (KAZ)
| 4 | ||||||||||||||
Repechage
| Repechage round 1 | Repechage round 2 | Bronze medals | ||||||||
| Albin Olofsson (SWE) | 7 | Albin Olofsson (SWE) | 2 | |||||||
| Daler Rezazade (TJK) | 3 | Dmytro Vasetskyi (UKR) | 1 | |||||||
| Ardit Ndoj (ALB) | 0 | Nikoloz Tchikaidze (GEO) | 2 | Nikoloz Tchikaidze (GEO) | 0 | |||||
| Nikoloz Tchikaidze (GEO) | 10 | Erkan Ergen (TUR) | 2 | Sergei Stepanov (RUS) | 10 | |||||