Iyo-Matsuyama Domain (伊予松山藩, Iyo-Matsuyama-han) was a feudal domain under the Tokugawa shogunate of Edo period Japan, in what is now central Ehime Prefecture on the island of Shikoku. It was centered around Matsuyama Castle, and was ruled throughout most of its history by the shinpan daimyō Hisamatsu-Matsudaira clan. Iyo-Matsuyama Domain was dissolved in the abolition of the han system in 1871 and is now part of Ehime Prefecture.
 Katō Yoshiaki was one of Toyotomi Hideyoshi's most trusted and experienced generals, having distinguished himself at the Battle of Shizugatake in 1583 and in the Japanese invasions of Korea, After Hideyoshi's death in 1598, Katō sided with Tokugawa Ieyasu at the Battle of Sekigahara in 1600, and his 60,000 koku holdings in Masaki in Iyo Province were expanded to 200,000 koku. He relocated his seat to Matsuyama Castle and this marked the beginning of Iyo-Matsuyama Domain. In 1627, he was transferred to Aizu Domain, and replaced by Gamō Tadatomo from Kaminoyama Domain in Dewa Province, who died without heir in 1634.
 The Tokugawa shogunate then assigned Matsudaira Sadayuki from Kuwana Domain to govern the territory, which was reduced in size to 150,000 koku.  His branch of the Matsudaira clan would govern Iyo-Matsuyama Domain to the Meiji restoration. Although prosperous in its early years, the domain was hard hit by famine caused by droughts and floods during the Kanbun and Enpo eras (1661–1680), and financial difficulties continued thereafter. In particular, the Kyōhō famine of 1732 was especially severe and the 5th daimyō. Matsudaira Sadahide was severely criticized by this shogunate for mismanagement when it was revealed that although 3500 commoners had died of starvation, his samurai continued to enjoy lives of dissipation. Despite constant financial issues, the tenshu of Matsuyama Castle was rebuilt in 1854 by the 12th daimyō, Matsudaira Katsuyoshi, although it had been destroyed by lightning seventy years previously in 1784. In 1859, Matsudaira Katsunari, the 13th daimyō, was ordered by the shogunate to construct coastal artillery batteries at Kanagawa in Musashi Province in response to the Perry Expedition. During the Bakumatsu period, the domain was strongly pro-shogunate, and was in the vanguard of the 1864 First Chōshū expedition. During that battle, Matsuyama troops looted and massacred the inhabitants of Suō-Ōshima island, which set the seeds for a strong enmity between Chōshū Domain and Matsuyama. The 14th daimyō, Matsudaira Sadaaki was appointed rōjū in 1867. During the Boshin War, he guarded the Umeda area of Osaka, but on hearing that Shogun Tokugawa Yoshinobu had abandoned his forces during the Battle of Toba-Fushimi, returned to Matsuyama. The domain surrendered to the imperial side under the conditions that it pay a 150,000 ryō fine to the Imperial Court and that Matsudaira Sadaaki resign and be placed under house arrest through the intercession of Tosa Domain, who was wary of Chōshū's increasing influence and belligerence. Afterwards, the Meiji government ordered Sadaaki to change his family name from 'Matsudaira' to 'Hisamatsu.' In 1871, the domain became "Matsuyama Prefecture" due to the abolition of the han system. Later, it was incorporated into Ehime Prefecture via "Sekitetsu Prefecture".
 In 1887, the family was granted the title of count (hakushaku) under the kazoku peerage system. The clan's Takayashiki residence in Edo was the location where Horibe Yasubei and 11 other of the Forty-seven rōnin of the Ako incident committed seppuku in 1703. After the Meiji restoration, the estate was sold to Matsukata Masayoshi and subsequently became the site of the Italian embassy in Tokyo.
 As with most domains in the han system, Matsuyama Domain consisted of several discontinuous territories calculated to provide the assigned kokudaka, based on periodic cadastral surveys and projected agricultural yields.