Oka Echizen-no-kami served as a bushō during the Azuchi-Momoyama and early Edo periods.  He was a retainer of the Bizen-Ukita clan.

Echizen-no-kami was born as the son of Oka Ietoshi (Buzen-no-kami), a retainer of Ukita Naoie.

His relationship to Oka Gōsuke, a servant cherished by Naoie, is uncertain.

After the death of Ietoshi, Echizen-no-kami served as a senior retainer of Ukita Hideie.  In 1599, owing to an internal disturbance in the Ukita clan, Echizen-no-kami came into conflict with Hideie and absconded, entering into service for Tokugawa Ieyasu.

In 1614, his son, Oka Heinai, was accused of harboring Hara Tanenobu (who had been banished under the order prohibiting the practice of Christianity) and removed from his position.  By disowning Heinai, Echizen-no-kami was pardoned by the Edo bakufu but then Heinei, through the assistance of his father-in-law, Akashi Teruzumi, entered Ōsaka Castle.

As a result, it appears that Echizen-no-kami was suspected of colluding and after the fall of Ōsaka Castle, sentenced to death.  He committed seppuku at the Myōken Temple in Kyōto.  His son, Heinai, was murdered and his head left exposed to the elements.

Echizen-no-kami’s grandson, 寿元 (the son of Oka Ienari, Echizen-no-kami’s third son), served as a physician to the Tokugawa family bringing honor to the family name.