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) B23, the designation of Monaro Highway in Victoria, Australia Docklands Light Railway B23 Stock, a light metro train in London