AHAS may refer to:

• Acetolactate synthase, a protein
• Avian Hazard Advisory System, a bird avoidance model developed by the United States Air Force

• Little Ladies of the Night
• Little lady's tresses
• Little Lake Bonnie
• Little Lake Bonny
• Little Lake (Peterborough)
• Little Lambkins
• Little laughing leek orchid
• Little Laurel Branch
• Little, Lawrence
• Little-leaf angelica
• Littleleaf buttercup
• Little leaf butter cup
• Little leaf buttercup
• Littleleaf, Charles
• Littleleaf horsebrush
• Littleleaf huckleberry
• Littleleaf linden
• Littleleaf mock-orange
• Littleleaf mock orange
• Littleleaf moonpod
• Little leaf notcher
• Littleleaf pixiemoss
• Littleleaf sensitive-briar
• Littleleaf sumac
• Little League home run