- Birth: 1532
- Death: 1557
- Other name: Ôtomo Haruhide
- Titles: Sakyô-daiyû
- Distinction: Lord of Suo and Nagato
Yoshinaga was a younger brother of Ôtomo Sôrin and the son of one of Ôuchi Yoshioki's daughters. He was at first known as Haruhide, the 'haru' being presented by the shôgun Ashikaga Yoshiharu. His name was later changed to Yoshinaga, in this case being awarded 'yoshi' from shôgun Ashikaga Yoshiteru. He was to be adopted into the Ôuchi family and in 1544 was presented to Ôuchi Yoshikata. The following year, however, Yoshikata's son Yoshihiro was born and so the planned adoption was called off. When Oûchi Yoshitaka was overthrown in 1551, Sôrin and Sue Harukata agreed to make Yoshinaga the new lord of the Oûchi, though he acted as a puppet to Sue. Following Môri Motonari's victory at Miyajima in 1555 and death of Sue, Yoshinaga's position was steadily weakened until he was forced to commit suicide as Motonari marched against Yamaguchi in 1557.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005