| Order: | Lord of Shōzui Castle |
| Termstart: | 1562 |
| Termend: | 1587 |
| Predecessor: | Miyoshi Yoshikata |
| Sogō Masayasu | |
| Native Name: | 十河 存保 |
| Birth Date: | 1554 |
| Birth Place: | Shōzui Castle |
| Death Place: | Battle of Hetsugigawa, Bungo Province |
| Allegiance: | Miyoshi clan Toyotomi clan |
| Rank: | Daimyo |
| Unit: | Sogō clan |
| Commands: | Shōzui Castle |
| Relations: | Miyoshi Yoshikata (father) Sogō Kazumasa (adoptive father) |
| Signature: | Kaō of Sogō Masayasu.svg |
| Signature Size: | 100px |
was a Japanese samurai of the Sengoku period.He was second son of Miyoshi Yoshikata who was adopted by Sogō Kazumasa from the Sogō clan.[1]
In 1582, Masayasu was defeated by Chōsokabe Motochika`s large army during the battle of Nakatomigawa, abandoned Shōzui Castle and asked Toyotomi Hideyoshi for help.[2] [3]
In 1585, he participated in Hideyoshi's successful campaign in Shikoku against Chosokabe clan.
In 1587, He died during the Kyushu campaign against the Shimazu clan as a result of Sengoku Hidehisa`s reckless actions at the battle of Hetsugigawa.[4]