It is said that name "Yawatahama" (八幡浜) comes from long ago when debris from a festival at the main Hachiman (八幡) shrine in Usa, Ōita, floated up on the beach (浜) in what is now modern-day Yawatahama. In 1889, during the Meiji Period the Yawatahama became a city under the new municipal system.