Athanasios Diakos
| General Athanasios Diakos Αθανάσιος Διάκος | |
|---|---|
| Portrait by Dionysios Tsokos | |
| Native name | Αθανάσιος Νικόλαος Μασσαβέτας | 
| Birth name | Athanasios Nikolaos Massavetas | 
| Nickname(s) | Diakos (Deacon) Διάκος | 
| Born | 1788 or 1791 Ano Mousounitsa or Artotina, Ottoman Empire (now Greece) | 
| Died | 24 April 1821 (aged 30 or 33) Lamia, Ottoman Empire (now Greece) | 
| Allegiance | Revolutionary Greece | 
| Branch | Hellenic Army | 
| Years of service | 1821 | 
| Rank | General (posthumously) | 
| Commands | Commander of his armed band | 
| Wars | |
| Memorials | Athanasios Diakos (village) and others | 
| Other work | Monk Member of the Filiki Etaireia | 
Athanasios Nikolaos Massavetas or Grammatikos (Greek: Αθανάσιος Νικόλαος Μασσαβέτας-Γραμματικός; 1788 – 24 April 1821) also known as Athanasios Diakos (Greek: Αθανάσιος Διάκος) was a Greek military commander during the Greek War of Independence, considered a venerable national hero in Greece.