B18

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
 * 18th Street gang (Barrio 18)