Cardisoma guanhumi, also known as the blue land crab, is a species of land crab found in tropical and subtopical estuaries and other maritime areas of land along the Atlantic coast of the Americas, in the United States along the Gulf of Mexico, from Brazil and Colombia, through the Caribbean, to the Bahamas, and as far north as Sebastian, Florida. The species varies in colour from dark blue to brown or pale grey, and may grow to in width and weigh over .