Nikkō Tōshō-gū (日光東照宮^?) is a Shinto shrine located in Nikkō, Tochigi Prefecture, Japan. It is part of the "Shrines and Temples of Nikkō", a UNESCO World Heritage Site.

Tōshō-gū is dedicated to Tokugawa Ieyasu, the founder of the Tokugawa shogunate. Initially built in 1617, during the Edo period, while Ieyasu's son Hidetada was shogun, it was enlarged during the time of the third shogun, Iemitsu. Ieyasu is enshrined here, and his remains are entombed here.

During the Edo period, the Tokugawa shogunate carried out stately processions from Edo to the Nikkō Tōshō-gū along the Nikkō Kaidō. The shrine's annual spring and autumn festivals reenact these occasions, and are known as "processions of a thousand warriors."

Five structures at Nikkō Tōshō-gū are categorized as National Treasures of Japan, and three more as Important Cultural Properties. Additionally, two swords in the possession of the shrine are National Treasures, and numerous other objects are Important Cultural Properties. Famous buildings at the Tōshō-gū include the richly decorated Yōmeimon, a gate that is also known as "higurashi-no-mon." The latter name means that one could look at it until sundown, and not tire of seeing it. Carvings in deep relief, painted in rich colors, decorate the surface of the structure. The next gate is the karamon decorated with white ornaments. Nearby, a carving of the sleepy cat, "Nemuri-neko", is attributed to Hidari Jingorō.