Some say its name comes from a female cacique, named Loaíza or Yuíza, who governed the region formerly called Haimanio, on the shores of the Río Grande de Loíza. It is said that this cacique might have married a mulatto conquistador called Pedro Mejías, but there is no evidence of this. Other sources point to a Spanish landlord named Iñigo López de Cervantes y Loayza, who owned a lot of the territory, and was renowned among governors and colonists of the time.