Neoplagiaulacidae is a family of mammal within the extinct order Multituberculata.

Fossil remains are known from the Upper Cretaceous through to the latest Eocene/early Oligocene.

Representatives have been found in North America, Europe and Asia.

[3] Neoplagiaulacinae (Ameghino 1890) has been seen as a sub-family within Ptilodontidae (Cope, 1887).

The family is part of the suborder of Cimolodonta within the superfamily of Ptilodontoidea.