On 19 November 1847, Mario Gigliucci was born to Giovanni Battista and Clara (Novello) Gigliucci in the town of Fermo (Marche). Mario was the third of four children.
In the early 1860s, Mario and his brother Giovanni attended military colleges in Nice, France, and Genoa, Italy. In 1866 they both joined the Garibaldini Red Shirt volunteer army to fight against the Austrians.
The following year, in 1867, Mario went to Bologna to study engineering at the University of Bologna. There he was invited to London, England to visit his Novello relatives, where he met his future wife, Edith Mozley.