Which abbey church near Paris is considered the first Gothic building?

The abbey church near Paris considered the first Gothic building is the Basilica of Saint-Denis.

Its architectural importance centers on the choir rebuilt under Abbot Suger between 1140 and 1144. The design combined features that became hallmarks of Gothic architecture: pointed arches, rib vaults, tall slender supports, extensive stained glass, and an innovative ambulatory with radiating chapels. These elements allowed more light into the interior and created a stronger sense of height.

Saint-Denis was not simply an experimental church. It was a major pilgrimage site associated with Saint Denis, the patron saint of France, and became the traditional burial place of French kings and queens. Nearly every French monarch from the 10th century through Louis XVIII was buried there.

A common mix-up is calling Saint-Denis the first building to use every Gothic feature individually. Pointed arches and rib vaults existed earlier elsewhere; Saint-Denis is celebrated because Suger brought the emerging techniques together in a single influential design.