Nanocuris is an extinct genus of Deltatheridiidae from the Cretaceous of Canada (Saskatchewan) and United States (Wyoming - Lance Formation and Hell Creek Formation). Initially, it was classified in a proper family, Nanocuridae, in the clade Eutheria, but a reanalysis of a new specimen revealed a delthatheroid affinity of the genus.
It was the largest deltatheroidean. Alongside with the similarly sized Altacreodus, it likely replaced earlier Cretaceous eutriconodonts as a large sized predatory mammal.
Its closest relative is the smallest deltatheroidean, Gurbanodelta.