Inoue Masaharu (井上 正春, November 25, 1805 – March 28, 1847) was a daimyō and official of the Tokugawa shogunate during late-Edo period Japan.
He inherited the leadership of the Inoue clan and the position of daimyō of Tanakura Domain on his father's death in 1820.
In 1838, he was appointed Osaka-jō dai (Castellan of Osaka) and in 1840, ascended to the rank of Rōjū (Senior Councilor) in the service of Shōgun Tokugawa Ieyoshi.
In 1845, with the resignation of head Rōjū Mizuno Tadakuni over the failure of the Tenpō Reforms and subsequent exile from Hamamatsu Domain to Yamagata Domain in Dewa Province, Inoue Masaharu was able to achieve the Inoue clan's goal of returning to Hamamatsu after an absence of 28 years.
From his years in Tanakura in Mutsu, Masaharu brought back with him a considerable body of knowledge on cotton production as well as artisans to build new looms, thus developing a major new industry for Hamamatsu and source of income for the domain.