Preheat oven on broiler setting. Lightly grease a baking sheet.
In a medium bowl, mix together crushed saltine crackers, mayonnaise, brown mustard, onion, celery, and Old Bay seasoning. Gently stir in the crabmeat. Shape into 6 patties. Place on prepared baking sheet.
Broil crab cakes 8 to 10 minutes on each side, or until golden brown.