Gamō Hidenori served as a bushō during the Sengoku period. He was the sixteenth head of the Gamō clan.
Hideyuki was born as the eldest son of Gamō Hideyuki. In 1513, after the death of Hideyuki, Hidenori’s uncle, Gamō Takasato, aspired to lead the family. However, upon the wishes of Hidenori’s grandfather, Gamō Sadahide, Hidenori was appointed as the successor, whereupon Hidenori inherited the headship of the family and became the lord of the base of the Gamō clan at Otowa Castle in Ōmi Province. Hidenori wed the daughter of his uncle, Takasato, and, ostensibly maintained friendly relations with him. Nevertheless, Takasato was resentful over the allocation of territory so, in the seventh month of 1522, he rebelled with the support of Rokkaku Sadayori, laying siege to Hidenori at Otowa Castle.
Hidenori made strenuous efforts to defend the castle; but, without the prospect of reinforcements, his situation became increasingly dire. After holding out for eight months, on 3/8 of Daiei 3 (1523), he finally surrendered and vacated the castle. Through the mediation of Rokkaku Sadayori, Hidenori and Takasato reconciled, but Sadayori had backed Takasato so the conditions of the settlement were extraordinarily unfavorable to Hidenori. Based on this resolution, Hidenori transferred the headship of the family to Takasato’s eldest son, Gamō Sadahide (Hidenori’s younger nephew whose name was pronounced the same but written with a different character than Hidenori’s grandfather), and was compelled to depart Otowa Castle which was left to ruin.
Having been ousted from Otowa Castle, Hidenori made a new base at one of the outlying castles named Kaigake Castle. In the twelfth month of 1525, Hidenori was murdered at Kaigake Castle. He did not have children, while his younger sister became a nun, so the lineage of Hideyuki (the main branch of the Gamō family) came to an end. Thereafter, the descendants of Takasato acquired the remaining territory and were regarded as the main branch of the Gamō family in name and in fact.