The Battles of Kawanakajima (川中島の戦い, Kawanakajima no tatakai) were a series of battles fought in the Sengoku period of Japan between Takeda Shingen of Kai Province and Uesugi Kenshin of Echigo Province from 1553 to 1564. Shingen and Kenshin contested each other for control of the plain of Kawanakajima between the Sai River and Chikuma River in northern Shinano Province, located in the present-day city of Nagano. The battles were triggered after Shingen conquered Shinano, expelling Ogasawara Nagatoki and Murakami Yoshikiyo, who subsequently turned to Kenshin for help.

Five major battles of Kawanakajima occurred: Fuse in 1553, Saigawa in 1555, Uenohara in 1557, Hachimanbara in 1561, and Shiozaki in 1564. The most famous and severe battle was fought on 18 October 1561 in the heart of the Kawanakajima plain, thus being known the Battle of Kawanakajima. The battles were ultimately inconclusive and neither Shingen nor Kenshin established their control over the plain of Kawanakajima.

The Battles of Kawanakajima became one of "the most cherished tales in Japanese military history", the epitome of Japanese chivalry and romance, mentioned in epic literature, paintings, woodblock prints, and movies.

The battles were part of the 16th-century Sengoku period, also known as the "Warring States Period", and were little different from other conflicts. After the Ōnin War (1467–77), the Muromachi shōgun's system and taxation had increasingly less control outside the province of the capital in Kyoto, and powerful lords (daimyōs) began to assert themselves. Such lords gained power by usurpation, warfare or marriage—any means that would safeguard their position. It was manifested in yamajiro ("mountain castles"), which overlooked the provinces.

In 1541, Shingen began his conquest of Shinano Province. In 1550, Shingen advanced once again into Shinano and quickly conquered Hayashi Castle, Kiribara and Fukashi Castle by siege. These had been controlled by Ogasawara Nagatoki, who fled to Murakami Yoshikiyo. In October 1550, Shingen began the Sieges of Toishi Castle, from which position he intended to carry out the final attack on the main Murakami castle of Katsurao. However, in November the siege was abandoned and Shingen's army was counterattacked by Murakami, and almost routed. The following year, though, Murakami was forced to leave the castle and the successful Siege of Katsurao (1553) ensued.

The first battle of Kawanakajima, also known as the "Battle of Fuse", was fought in 1553. Although regarded as the first battle, it is related to the two battles of Hachiman fought in the same year south of the plain.

Twelve days after taking Katsurao Castle, Shingen penetrated far into the Kawanakajima plain along the eastern bank of the Chikumagawa River. Uesugi Kenshin marched up the western bank to support Murakami Yoshikiyo, and the two armies encountered each other at a shrine of Hachiman (place within modern Yashiro) on June 3, 1553. After Takeda withdrew, Uesugi continued his march and laid siege to Katsura, but was unable to capture it.

In September, Takeda returned to crush the remaining Murakami forces around Shioda. Wada was taken on September 8 and Takashima on the 10th. In both cases the entire garrison was put to death as a warning to other Murakami holdouts. Murakami Yoshikiyo retreated from Shioda on 12 September 1553 and about 16 of the clan's outposts in Shinano surrendered to Takeda. Shingen pursued Yoshikyo across the Chikumagawa River but was turned back by Kenshin's reinforcements at the Battle of Fuse. Kenshin pursued Shingen, winning another battle at Hachiman. The victorious Uesugi forces went on to take Arato castle before winter forced both sides to disengage.^{[citation needed]}