Ottone del Carretto (died 1237×42), a patron of troubadours and an imperialist, was the margrave of Savona (c.1185–91) and podestà of the Republic of Genoa (1194–95) and of Asti (1212). He was the founder of the Del Carretto family.
The earliest record of Ottone dates to 1179, when he subscribed with his younger brother, Enrico (II), to the charter of their father, Enrico Guercio, whereby the commune of Savona was granted fiscal and judicial independence. In 1181, the brothers again subscribed their father's chater, this time granting the commune of Noli the right to hold a market and to fortify itself, in return for the commune's recognition of the marquis's suzerainty, including the right to fodder and the ban.
The same year (1181), Ottone, still a minor, witnessed the treaty between Manfred II of Saluzzo, his relative, and the commune of Alba. As a result of this agreement, Manfred released some merchants of Alba whom he had been holding hostage.
The first act of Ottone and Enrico after they had come of age was to swear to the Compagna of the Republic of Genoa, on 20 July 1182, that they would reside in the city for three months of the year during time of war and for one month a year during peacetime. After the death of Enrico Guercio, between 1184 and 1186, the brothers divided their inheritance. Whether this was in accordance with their father's testament or of their own accord is unclear. Both brothers held the title "margrave (marchio) of Savona".
Ottone, as the elder brother, took Savona, the lordships of Albisola and Quiliano and the castles of Cairo, Dego and Cortemiglia. These villages lay on the road from coastal Savona to the subalpine Langhe. The cities of Savona and Noli were now largely independent of seignorial authority, and in the former the family's power was wielded most effectively by the bishop, Ambrogio, another younger brother of Ottone.