Isabela (Ĭzəbĕl´ə, Span. ēsäbā´lä), province (1990 pop. 1,080,341), NE Luzon, the Philippines. The capital is Ilagan. The fertile Cagayan River valley, which is in the central and eastern part of the province, is a leading tobacco- and cacao-producing region. The rugged Sierra Madre on the east is mineral rich; iron, nickel, and copper deposits, as well as the nation's major manganese mines, are there.

Isabela (ēsäbā´lä), ruins of a town on the north shore of Hispaniola, in the Dominican Republic, at the base of Cape Isabela. Believed to have been founded by Columbus (c.1494), it was one of the first Spanish settlements in the New World.

Isabela, island, Ecuador: see Galápagos Islands.