The Italian surname Trimarchi is of occupational origin. Surnames of occupational origin are derived from the occupation or trade of the original bearer of the name.

In this instance, the surname Trimarchi derives from the Italian word " trimarco " which is further derived from the Byzantine word " turmarches " meaning " governor ". In Greek and Byzantine, the word " arches " from " archein ", means "to order, command, rule", or to be a chief or leader of a " turmo ". In LATIN, the word " turmo " means " troop " or " squadron ". Thus the Italian word " trimarcho " means a commander of a squadron, or commander of a zone which was subdivided for administrative or military purposes.

It is thus logical to assume that the progenitor of the surname Trimarchi was one whose occupation was that of a military commander who held a rather high position. Before the inception of a hereditary system of surnames, it was common for someone to be known in his community by his occupation, especially if it was distinctive in any way. This served as a convenient means of identification.

The surname Trimarchi and its variant form Trimarco are found primarily in the areas of eastern Sicily, most frequently in the area of Messina, and also in the southern part of the Italian mainland.

In the archives we find evidence of a Trimarchi family from Messina. This family was founded by one Polidora, who was a follower of King Alfansa of Aragon during the conquest of the kingdom of Naples, and later settled in Messina.

The family possessed the Baronies of Banderia and Villa Marchese and was inducted into the Order Knights of the Malta of the in 1592