SS Manasoo (originally named Macassa) was a steel-hulled Canadian passenger and package freighter in service between 1888 and 1928. She was built in 1888 in Port Glasgow, Scotland, by William Hamilton & Company for the Hamilton Steamboat Company of Hamilton, Ontario. During this time, she mainly carried passengers between Hamilton and Toronto, Ontario. Macassa was lengthened in Collingwood, Ontario, in 1905. She was sold twice before being sold to the Owen Sound Transportation Company, Ltd., and was rebuilt and renamed Manasoo; after the sale, she mainly operated between Sault Ste. Marie and Owen Sound, Ontario.