The Miyoshi clan (三好氏) was an ancient Japanese family from the Awa province of Shikoku Island.
This family was descended from Emperor Seiwa (850-880) and the Minamoto Clan; it was also a younger branch of the Ogasawara and Takeda clans.
At the beginning of the 14th century, Nagafusa Ogasawara settled on the island of Shikoku. His 8th generation descendants settled in Miyoshi (Awa province) and took the family name of this city.
They were important vassals of the Hosokawa clan which was at that time very powerful on the island.
During the Sengoku, they controlled several provinces such as Settsu and Awa. In 1565, Miyoshi Yoshitsugu and three members of the Miyoshi council (Miyoshi triumvir composed of Iwanari Tomomichi,
Miyoshi Masayasu and Miyoshi Nagayuki) and Matsunaga Hisahide laid siege to the complex of buildings which later became Nijo castle and overthrew the shogun Yoshiteru Ashikaga and replaced him with his younger brother Yoshiaki Ashikaga three years later.
The shogun's mother also died in the battle. Although afterwards their influence was slightly overshadowed by that of the Ogasawara, a clan to which they remained closely related, they remained a significant political force during the Edo period.
Their vassals were the Hatano and Matsunaga clans (including Matsunaga Hisahide and his son Hisamichi Matsunaga).