Okuyama Masayuki served as a bushō and daimyō during the Azuchi-Momoyama and early Edo periods.

Masayuki was born as the son of Okuyama Moriaki, a bushō and daimyō who was the son of Sakuma Morishige, a retainer of Oda Nobunaga.

In 1594, Masayuki inherited the landholdings of his father totaling 11,000 koku in Echizen Province.  In 1600, during the prelude to the Battle of Sekigahara, Masayuki joined the Western Army and led 500 soldiers to launch an assault against the Daijō Temple in the Enuma District of Kaga Province.  Owing to the loss by the Western Army at the main Battle of Sekigahara, he fled in defeat and, after the war, he lost his fief.  He then entered the priesthood, adopting the name of Sōha, and resided in Kyōto.

Masayuki died on 1/18 of Shōhō 2 (1645).

His eldest son, Okuyama Shigenari, was engaged as a hatamato, or direct retainer to the Edo bakufu, with a stipend of 1,000 koku.