This thesis investigates the influence of the Tiffany Studios in ecclesiastical stained glass windows of Indianapolis, Indiana. The Tiffany Studios was a leading stained glass manufacturer at the turn of the century and popularized the use of opalescent glass in stained glass commissions. The following study will briefly look at the history of stained glass, discuss the life of Louis Comfort Tiffany, characterize the work of the Tiffany Studios, and evaluate the ecclesiastical stained glass windows located in Center Township commissioned between 1880-1930. The evidence contained within the stained glass summaries suggests that Tiffany Studios did influence the commission of stained glass windows in Indianapolis during the period under review. / Department of Architecture