Nitta Yoshisada (新田 義貞?, 1301 – August 17, 1338) was the head of the Nitta clan in the early fourteenth century, and supported the Southern Court of Emperor Go-Daigo in the Nanboku-chō period, capturing Kamakura from the Hōjō clan in 1333.
Long an enemy of Ashikaga Takauji, Nitta Yoshisada is often blamed for the split between the Northern and Southern Courts, as he fought against the Ashikaga and for the emperor, Emperor Go-Daigo. This rivalry came largely from the fact that the Ashikaga were ranked above the Nitta, despite their being descended from a younger ancestor; since the ancestors of the Nitta did not fight alongside their Minamoto cousins in the Genpei War, they were never accorded power or prestige at Kamakura.
In 1331, after being ordered by the bakufu (shogunate) to join an army at the Chihaya fortress, Nitta was ordered by Prince Morinaga and Emperor Go-Daigo to strike at the Hōjō, so he left his post. Returning to his home province of Kozuke, Yoshisada rallied the aid of other descendants and vassals, including his brother Yoshisuke of the Minamoto clan, and began to march toward Kamakura through Musashi. On the approaches to the city, Nitta enjoyed some early victories, routing the Hōjō defenders and pursuing them towards the city.