Blue crab may refer to:

• Blue Crab 11, an American sailboat design
• Callinectes sapidus – Chesapeake or Atlantic blue crab of the West Atlantic, introduced elsewhere
• Cardisoma guanhumi – blue land crab of the West Atlantic
• Discoplax celeste – blue land crab of Christmas Island
• Paralithodes platypus – blue king crab of the North Pacific
• Portunus pelagicus – blue swimmer crab of Australia and Southwest Pacific
• Portunus segnis - a Western Indian Ocean species, was recently recorded in Tunisian waters, where it is invasive
• Portunus trituberculatus – Japanese blue crab of the Northwest Pacific

This page is an index of articles on animal species (or higher taxonomic groups) with the same common name (vernacular name). If an internal link led you here, you may wish to edit the linking article so that it links directly to the intended article.