Saint Demetrios Greek Orthodox Church is a church in Seattle, Washington. It is part of the Greek Orthodox metropolis or diocese of San Francisco, within the Greek Orthodox Archdiocese of America. It is Seattle's oldest Greek Orthodox congregation. The present St. Demetrios Church in the Montlake neighborhood (completed in 1962) was designed by Paul Thiry, one of the principal architects of the Century 21 Exposition Seattle's World's Fair that same year and of the Museum of History and Industry (MOHAI), formally in Montlake.