1990–91 Mexican Segunda División season

The 1990–91 Segunda División was the 42nd season of the Mexican Segunda División. The season started on 3 August 1990 and concluded on 17 July 1991. It was won by Atlante.

Changes

 * León was promoted to Primera División.
 * Atlante was relegated from Primera División.
 * Querétaro was promoted to Primera División after bought the Tampico Madero franchise. Pioneros de Cancún bought the Querétaro spot in Segunda División.
 * Cachorros Zamora and Guerreros Acapulco were promoted from Segunda División B.
 * Zitlaltepec was promoted from Tercera División.
 * SUOO, Galicia and Ayense were relegated from Segunda División.
 * Petroleros Salina Cruz license was bought by Real Celaya.