9B

9B, 9b or IX-B may refer to :
 * Route 9B (WMATA), a bus route operated by the Washington Metropolitan Area Transit Authority
 * Stalag IX-B, a World War II German Army prisoner of war camp at Wegscheide close to Bad Orb
 * 9B (TV series), a 1988 TV series with Canadian actor Zachary Ansley
 * Boron-9 (9B), an isotope of boron
 * HAT-P-9b, an extrasolar planet