A variety of wild and domestic mammals from Manitoba were examined for external parasites, and fleas were recovered from 15 species. A total of 17 species of fleas were collected, of which 10 were first records for Manitoba, one was a subspecies new to the area, and 7 were recorded from new hosts. Orchopeas leucopus and Monopsyllus wagneri were the most abundant species taken from wild animals, being found on the most abundant host, Peromyscus maniculatus. Flea populations reached a peak in late summer, and were found in greater numbers on juvenile than on older hosts, on lactating than on other adults, and on solitary than on gregarious species.