A-line or A Line may refer to:
Transport
A (New York City Subway service), rapid transit line
A Line (Los Angeles Metro), a light rail line in Los Angeles County, California
A Line (RTD), commuter rail line between Denver and Aurora, Colorado
Atlantic Coast Line Railroad, rail line in Florida
Metro A Line (Minnesota), a bus rapid transit line in Minneapolis, Saint Paul, and Roseville, Minnesota A-Line (Hamilton), planned rapid transit line in Hamilton, Ontario, Canada RapidRide A Line, bus route in King County, Washington Line A (Buenos Aires Underground), Argentina RER A, commuter rail line in Paris, France A (Los Angeles Railway), former streetcar service
Other uses
A-line (clothing), a style of skirt or dress
Arterial line, a thin catheter inserted into an artery
A-line - a finding in medical ultrasound of the lung
See also
A-A line
Aline (disambiguation) Line A (disambiguation) Line (disambiguation)