Guadalajara is a province of central Spain, in the northern part of the autonomous community of Castile-La Mancha. It is bordered by the provinces of Cuenca, Madrid, Segovia, Soria, Zaragoza, and Teruel.

Its population is 177,761 (2002). Its capital is Guadalajara, where nearly 40% of the province's population lives. There are 288 municipalities in Guadalajara, of which more than three-quarters are villages with populations less than 200.