Nuevo Santander (New Santander) is a region of the Viceroyalty of New Spain, corresponding generally to the modern Mexican state of Tamaulipas and southern Texas.

Nuevo Santander is named after Santander, Cantabria, Spain, and settled by Spanish American colonists in a concerted settlement campaign peaking in 1748-1750.

It fell under the jurisdiction of the Real Audiencia of Guadalajara in judicial matters, and in 1776 Nuevo Santander becomes part of the semi-autonomous Provincias Internas.