The rocky islands and rugged habitats of the outer Oregon coast and the low flat islands of the Columbia River estuary provide habitat for approximately 1.3 million nesting seabirds representing 15 species. Current and historical information on colony locations and estimates of breeding seabirds were compiled into databases, for all known seabird colonies in Oregon. A total of 393 colonies were identified, and maps and data tables for each colony are presented in this catalog. The data tables include counts of nests and birds, where available, and estimates of the number of breeding birds for each species at a colony. Specific information regarding date, observers, type of survey, quality of the estimate, and source of the data are provided for each record. The geographic scope of this catalog encompasses seabird colonies in marine and estuarine environments. Marbled Murrelets, which nest solitarily in habitats distinctly different from the rest of the seabird community, are not included in this catalog.