B18 or B-18 may refer to: Alton Bay Seaplane Base (FAA LID: B18) B-18 Bolo, an American bomber aircraft by Douglas based on the Douglas DC-2 B 18, a Swedish bomber aircraft made by SAAB B18 (New York City bus) serving Brooklyn B18 road (Cyprus) Caro-Kann Defence, in chess (Encyclopaedia of Chess Openings code B18) HLA-B18, an HLA-B serotype Honda B engine Volvo B18 engine Boron-18 (B-18 or 18B), an isotope of boron LNER Class B18, classified B1 until 1943