Coahuila y Tejas (Coahuila and Texas) was one of the constituent states of the newly established United Mexican States under its 1824 Constitution.

It had two capitals: first Saltillo, and then Monclova. For administrative purposes, the state was divided into three districts: Béxar, comprising the area covered by Texas, Monclova, comprising northern Coahuila, and Río Grande Saltillo, comprising southern Coahuila.

The state remained in existence until the adoption of the 1835 "Constitutional Bases", whereby the federal republic was converted into a unitary one, and the nation's states, (estados), were turned into departments (departamentos). The State of Coahuila y Texas was split in two and became the Department of Coahuila and the Department of Texas.

Both Coahuila and Texas seceded from Mexico because of Santa Anna's attempts to centralize the government. Texas eventually seceded and became the independent Republic of Texas, which is now a federated state of the United States of America. Coahuila joined with Nuevo León, and Tamaulipas to form the short-lived Republic of the Rio Grande.