Ashikaga Yoshiaki (Oyumi Kubo)
- Death: 1538
- Distinction: Shimôsa warlord
- Title: Koga Kubo
- Sons: Ashikaga Yoshizumi and Ashikaga Yorizumi
Yoshiaki was a son of Ashikaga Masauji (1466-1531) and a grandson of Ashikaga Shigeuji. He was established at Oyumi castle in Shimôsa Province around 1525 by the Takeda of Kazusa (Oyumi thus became nicknamed the headquarters of the Oyumi kubô and Yoshiaki was called the Oyumi Gosho). He led troops to join Satomi Yoshitaka in an attack on the Hôjô domain that culminated in the crushing defeat at Konodai in 1538. In the course of the battle, Yoshiaki was killed along with his son Yoshizumi. He should not, of course, be confused with the Ashikaga Yoshiaki whom Nobunaga established in Kyoto in 1568 and who proved to be the last Ashikaga shôgun.