Maurilio Montaño Oliver was born in Pachuca de Soto, Hidalgo, Mexico, on 13 September 1913. He was the eldest of five children born to Carlos Montaño and Maria Concepción Oliver. His mother died at the age of 92.

At some point, he married Margarita Hernández. The couple had eight children. Their youngest son was a volunteer lifeguard, and their only child who was deceased as of June 2022. For 54 years, spanning from the age of 16 until his retirement at 70, he served as an employee at the Beneficio Loreto plant, which was owned by the Real del Monte y Pachuca mining company. His role was not within the mines themselves, but rather in the sampling areas where he assessed the quality of the metal.

In 2020, he stopped walking due to the loss of mobility in one of his legs. As of June 2022, his sole living sibling was Rebeca, the youngest among the five. During this period, he resided with his son, Ricardo Javier, and his daughter-in-law.

Maurilio Montaño Oliver passed away in Pachuca de Soto, Hidalgo, Mexico, on 20 August 2023, at the age of 109 years, 341 days.