This document is a thesis presented by Joanna April De Leon Lumbad to the faculty of St. Scholastica's College in Manila for the degree of Bachelor of Science in Interior Design. The thesis explores defining the Filipino cultural identity through Filipino avant-garde in performing arts theaters. It discusses the history of performing arts theaters and Philippine theater. Through interviews with theater experts and observations of existing theaters, the thesis examines how theater design has adapted over time to different influences and seeks to determine if an avant-garde concept can help establish a uniquely Filipino style.