GA1 or GA-1 may refer to:
Science and Medicine GA1, Glutaric aciduria type 1, an inherited genetic disorder GA1, Gibberellin A1, a form of the gibberellin plant hormone
Transport Boeing GA-1, a 1921 American armored triplane Celair GA-1 Celstar, South African aerobatic glider GA 1, the U.S. Route 27 in Georgia, USA
Other Ga1, Golden Axe (video game), a side-scrolling arcade hack and slash game released in 1989 by Sega GA-1, Georgia's 1st congressional district GA1, the United Nations General Assembly First Committee (also DISEC or C1)