Species of Canacidae sensu lato, including the subfamilies Canacinae, Pelomyiinae, and Tethininae, from the Delmarva states are revised. Included are nine species in six genera. Taxonomic categories from family to species are diagnosed and appropriate synonymy, illustrations, maps, and information on the natural history are provided for each species. A lectotype is designated for Rhicnoessa parvula Loew. Anthomyza cinerea Williston, 1896 and Rhicnoessa bermudaensis Melander, 1952 are determined to be conspecific with Rhicnoessa willistoni Melander, 1913 with the latter being the senior synonym.