The Kishū Domain (紀州藩, Kishū-han), also referred to as Kii Domain or Wakayama Domain, was a feudal domain in Kii Province, Japan. This domain encompassed regions in present-day Wakayama and southern Mie prefectures and had a substantial income of 555,000 koku. The administrative center of the domain was located at Wakayama Castle, which is situated in present-day Wakayama, Wakayama Prefecture.

After the Battle of Sekigahara in 1600, Asano Yukinaga, the lord of Kai Province, was granted Kii Province. This led to the establishment of the Kishu Domain, which governed the Asano clan of Tozama. However, in 1619, the Asano clan was relocated to the Hiroshima Domain in Aki Province under the leadership of Fukushima Masanori. At the same time, Tokugawa Yorinobu, the tenth son of Tokugawa Ieyasu and the former lord of the Sunpu Domain, merged the former territory of Asano with 555,000 koku. This expansion included Minami Ise and Kishu, which was the main domain governed by the Kii-Tokugawa clan. As a result, the domain was officially established.

Tokugawa Yorinobu recruited Rōnin and raised suspicions during the Keian Incident in 1651, allegedly challenging the Shogun. Tokugawa Tsunanori, Yorinobu's grandson and third lord of the domain, married Tokugawa Tsuruhime, the eldest daughter of the fifth shogun, but died prematurely. Tokugawa Yoshimune, Tsunanori's younger brother and 5th lord of the domain, became the 8th Shogun after a series of events, bringing over 200 feudal retainers from the Kishū clan to Edo. Tokugawa Munenao, the sixth lord of the domain, who inherited the clan from the branch domain after leaving Yoshimune, overcam the financial difficulties caused by the Kyoho Famine, which lost 57% of the amount of the amount of koku, with 20,000 ryo of public money borrowed, but after that, he followed the way to make up for this budget deficit with public money. The Wakayama Domain deepened its financial dependence on the shogunate because it was close to the Shogun, and on the other hand, this became a factor that put pressure on the shogunate's finances.

The 11th lord of the domain, Tokugawa Nariyuki, lost his worship debt during the Tenmei era, and borrowed a new 20,000 bale from the shogunate's Osaka Kurazumemai. The balance of the debt reached 45,000 ryo.

Keifuku, the 13th lord of the domain, was the grandson of the 11th Shogun Tokugawa Ienari, and in 1858, he inherited the Shogun family after Iesada, the 13th Shogun without children, and became the 14th Shogun Iemochi. All the successive shoguns after the 8th Shogun Yoshimune were occupied by the Kishu Domain and the Hitotsubashi-Tokugawa family, which was a branch of it.

Following the abolition of the han system in July 1871, significant changes occurred in the administrative divisions of Japan. The territories of Kishū, Tanabe, and Shingū were transformed into separate entities known as Kishū Prefecture, Tanabe Prefecture, and Shingū Prefecture, respectively. However, these prefectures were short-lived as they were dissolved in November of the same year. This dissolution led to the establishment of the present-day Mie and Wakayama prefectures, which continue to exist to this day.

• List of Han
• Abolition of the han system