B23

B23 may refer to:
 * A human nucleolar protein also known as NPM1
 * The 2.3L, pre-revision variant of the Volvo Redblock engine
 * Bundesstraße 23, federal highway in Germany
 * B-23, national highway in Catalonia
 * B-23 Dragon, a 1930s bomber aircraft
 * B-23 (Michigan county highway)
 * DLR B23 stock, a passenger train on the Docklands Light Railway in London, UK