The Interlake Steamship Company is an American freight ship company that operates a fleet on the Great Lakes in North America. It is now part of Interlake Maritime Services.

MV Paul R. Tregurtha is a Great Lakes-based bulk carrier freighter. She is the current Queen of the Lakes, an unofficial but widely recognized title given to the longest vessel active on the Great Lakes. Launched as MV William J. De Lancey, she was the last of the thirteen "thousand footers" to enter service on the Great Lakes, and was also the last Great Lakes vessel built at the American Ship Building Company yard in Lorain, Ohio. The MV Paul R. Tregurtha is the current flagship for the Interlake Steamship Company.