Guanacaste can refer to:

Guanacaste (tree), the common tropical American tree Enterolobium cyclocarpum

Places Belize Guanacaste National Park (Belize), a small national park in Belize Costa Rica Guanacaste Province, a province of Costa Rica Guanacaste National Park (Costa Rica), a small national park in Costa Rica Guanacaste Cordillera a mountain range in Costa Rica