"Blue" Mary Ryan, commonly known as "Blue Mary", is a Fatal Fury and The King of Fighters character. She is a detective primarily serving in South Town.
She has short, blonde straight hair and blue eyes. She wears a red bra-like crop top (later switched to blue in Real Bout Fatal Fury Special, a red cropped shirt in The King of Fighters), blue gloves that go with her baggy pants, brown boots that prevent her pants from hanging loose to the bottom, and a bomber jacket. Her most famous accessory is an oversized brown belt she wears on her hips.
Mary's fighting style is Sambo - a Russian hybrid combat style. Apart from assorted strikes and grapples, including a German suplex, her specialties include takedowns and submissions, including limb locks.
Terry Bogard is a close friend of hers, even teased as a love interest at times, though she is hesitant to commit due to the death of a previous lover. Mary is noted to have an alternate personality that comes out when she gets frustrated, one that is more sadistic in nature. She has a pet dog named Anton.
Blue Mary's appearance is openly acknowledged as inspired by Android 18 from Dragon Ball Z.