Sapi-an or Sapian is a 4th class municipality in the province of Capiz, Philippines. It belongs to the Second Congressional District of the Province of Capiz. The town's zip code is 5806.

On last count, Sapian has a total population of 25,316 people and 23,854 of the Sapianons are Catholics.

Sapian Bay which is situated in the northern part of the municipality is geographically joined with Capiz Bay. The 30 km² Sapian and Capiz shallow sea bays has extensive intertidal mudflats, sandy beaches, mangrove swamps, estuaries of several small rivers, and associated coastal lagoons and marshes.

Sapian Bay which opens up to the sea is a source of livelihood for many Sapianons. Marine produce from Sapian Bay include green mussels "tahong", oyster "talaba", lobster and different species of fish,and clams. Many lands near sea water were developed into fishponds that produce milkfish (bangus), prawns and crabs.

Another source of livelihood is agriculture. Carpets of rice fields, trees and flowers can be seen as one travels through Sapian along the national road which connect Roxas City to Iloilo and Aklan. The ricefield along the national road are slowly disappearing to give way to housing developments. Sapian's main agricultural produce are rice and coconuts.