A30 or A-30 may be:

• A30 road, a major road in England
• Austin A30, a 1950s British compact car
• English Opening, Encyclopaedia of Chess Openings
• Cruiser Mk VIII Challenger (A30)
• The Martin A-30 Baltimore, a United States built attack/bomber aircraft
• Aero A.30, a Czech light bomber developed in the late 1920s