Before the coming of the Spaniards, Catarman (also known as Calatman or Cataruman) was a settlement by the mouth of the river of the same name in the region called Ibabao.

The Spanish Conquistadors applied the term Ibabao to the northern part of Samar island when it established its civil government.

The similarities in the vocabularies and pronunciation of the dialects of these areas traces them to a common root as a people.

[5] Catarman lies on the northern part of Samar Island, bounded to the east by Mondragon, to the west by Bobon, to the south by Lope de Vega, to the southwest by Calbayog City, and to the north by the Philippine Sea.

On the Pacific coast are flat lowlands with the interior characterized by outlying low hills.