Nirengi Castle (Nirengi-jō) was a Japanese castle in what is now the city of Toyohashi, Aichi Prefecture, during the Sengoku Period. There are no extant structures left; however, a park was built on the site where the castle once stood, and a stone monument and some explanatory signboards were erected by the city.
In 1465, Toda Munemitsu (c. 1439–1508), a retainer of the Ashikaga shogunate was ordered to advance from Kyoto into Mikawa province, to hunt down members of the Maruyama and Ōhira families and to subdue the area. Munemitsu started with the Chita Peninsula, and proceeded southeast around Mikawa Bay and into the Atsumi peninusula, where he constructed Ōtsu Castle in 1479 and Tahara Castle in 1480 as bases for the prosecution of his campaign. With the Atsumi area subdued, he left Tahara Castle in the care of his eldest son, Norimitsu, and turned his attention to the east.