| Age | 73 (age at death) |
| Birthday | 1912 |
| Died | 24 December, 1985 |
| Nationality | Mexican |
| Occupation | Activist |
Demetrio Vallejo (1912 – December 24, 1985) was a railroad worker and union activist from Tehuantepec, Oaxaca, Mexico. Vallejo began working as a railroad employee in 1928, later joining the Partido Comunista Mexicano (PCM) in 1934. Vallejo was eventually promoted to Regional Director of the PCM in Oaxaca, however later expelled in 1946. In 1946, Vallejo joined the Unified Socialist Action (Spanish: Accion Socialista Unificada) and later the Mexican Worker-Peasant Party (Spanish: Partido Obrero-Campesino Mexicano (POCM) at its founding in 1950. Vallejo was a primary leader of the Mexican railroad strikes of 1958–59.
