Mainero is a municipality located in the Mexican state of Tamaulipas.
Its capital is called Villa Mainero and had 338 inhabitants during a 2020 INEGI census.
The municipality as a whole had 2 048 inhabitants.
Other localities include José Guadalupe Mainero, Guadalupe Mainero and Guadalupe Mainero.
[1] All named after Guadalupe Mainero (1856–1901), a Mexican journalist, teacher and governor of Tamaulipas between May 4, 1896 and July 31, 1901.