Tokugawa Yoshimune (徳川 吉宗; 27 November 1684 – 12 July 1751) was the eighth shōgun of the Tokugawa shogunate of Japan, ruling from 1716 until his abdication in 1745. He was the son of Tokugawa Mitsusada, the grandson of Tokugawa Yorinobu, and the great-grandson of Tokugawa Ieyasu. Yoshimune is known for repealing the ban on Western literature.

Yoshimune was not the son of any former shōgun. Rather, he was a member of a cadet branch of the Tokugawa clan. Tokugawa Ieyasu, the founder of the Tokugawa shogunate, well aware of the extinction of the Minamoto line in 1219, had realized that his direct descendants might die out, leaving the Tokugawa family at risk of extinction. Thus, while his son Tokugawa Hidetada was the second shōgun, he selected three other sons to establish the gosanke, hereditary houses which would provide a shōgun if there were no male heir. The three gosanke were the Owari, Kii, and Mito branches.

Yoshimune was from the branch of Kii. The founder of the Kii house was one of Tokugawa Ieyasu's sons, Tokugawa Yorinobu. Ieyasu appointed him daimyō of Kii. Yorinobu's son, Tokugawa Mitsusada, succeeded him. Two of Mitsusada's sons succeeded him, and when they died, Tokugawa Yoshimune, Mitsusada's fourth son, became daimyō of Kii in 1705. Later, he became shōgun.

Yoshimune was closely related to the Tokugawa shōguns. His grandfather, Tokugawa Yorinobu, was a brother of second shōgun Tokugawa Hidetada, while Yoshimune's father, Tokugawa Mitsusada, was a first cousin of third shōgun Tokugawa Iemitsu. Yoshimune thus was a second cousin to the fourth and fifth shōguns (both brothers) Tokugawa Ietsuna and Tokugawa Tsunayoshi, as well as a second cousin to Tokugawa Tsunashige, whose son became shōgun Tokugawa Ienobu.

Tokugawa Yoshimune was born in 1684 in the rich Kii Province, a region which was then ruled by his father, Tokugawa Mitsusada. Yoshimune's childhood name was Tokugawa Genroku (徳川 源六). At that time, his second cousin Tokugawa Tsunayoshi was ruling in Edo as shōgun. Kii was a rich region of over 500,000 koku, but it was still in debt and had a lot to pay back to the shogunate.

In 1697, Genroku underwent the rites of passage and took the name Tokugawa Shinnosuke (徳川 新之助). In 1705, when Shinnosuke was just 21 years old, his father Mitsusada and two older brothers died. Thus, the ruling shōgun Tokugawa Tsunayoshi appointed him daimyō of Kii. He took the name Tokugawa Yorikata (頼方) and began to administer the province. Nonetheless, great financial debt which the domain had owed to the shogunate since his father's and even grandfather's time continued to burden the finances. What made things worse was that in 1707, a tsunami destroyed and killed many in the coastal areas of Kii Province. Yorikata did his best to try to stabilize things in Kii, but relied on leadership from Edo.

In 1712, Shogun Ienobu died, and was succeeded by his son, the boy-shōgun Tokugawa Ietsugu. Yorikata decided that he could not rely on conservative Confucianists like Arai Hakuseki in Edo and did what he could to stabilize Kii Domain. Before he could implement changes, shōgun Ietsugu died in early 1716. He was only seven years old, and died without an heir. The bakufu thus selected the next shōgun from one of the cadet lines.

Yoshimune succeeded to the post of the shōgun in Shōtoku-1 (1716). His term as shōgun lasted for 30 years. He is considered among the best of the Tokugawa shōguns.