Yunagaya Domain (湯長谷藩, Yunagaya-han) was a minor fudai feudal domain under the Tokugawa shogunate of Edo period Japan. based in southern Mutsu Province in what is now part of modern-day Iwaki, Fukushima. It was ruled for the entirety of its history by the Naitō clan. The domain was initially known as Yumoto Domain (湯本藩, Yumoto-han)