The study begins with a general analysis of the ethnic composition of Hamilton's population and the changes which this composition has undergone since the beginning of the present century. The major part of the study then selects the most ethnically diverse sector of · the city, namely the Barton Street region, and subjects it to a detailed examination over a forty year period, using cross-sections of the years 1921, 1941 and 1961. For each year an analysis is made of the residential distribution of individual ethnic groups there, and the number and kind of their associated services and institutions. The area is then divided into regions and sub-regions of ethnicity for each of these years. Finally the changes occurring in the areal extent and ethnic content of such regions over the period of study are discussed and some explanations offered for them. / Thesis / Master of Arts (MA)