| Ο Ύμνος της 21ης Απριλίου | |
| English Title: | Anthem of the 21st of April |
| Prefix: | Unofficial |
| Country: | the Regime of the Colonels |
| Author: | George Oikonomidis |
| Lyrics Date: | 1967 |
| Composer: | George Katsaros |
| Music Date: | 1967 |
| Adopted: | 1967 |
| Until: | 1974 |
| Sound: | File:Anthem of The Greek Military Junta (1967-1974) - 'Ύμνος 21ης Απριλίου'.ogg |
| Sound Title: | Anthem of the 21st of April |
The Anthem of the 21st of April (Greek, Modern (1453-);: Ύμνος της 21ης Απριλίου) was the anthem of the ruling military regime during the Greek military junta of 1967–74, de facto used as an unofficial co-national anthem along with the Hymn to Liberty. The anthem glorifies the "national revolution" begun by the regime, which took power with the Coup d'état of 21 April 1967.