The LB&SCR B1 Class is a class of 0-4-2 express passenger steam locomotives. They were the last express passenger design of William Stroudley, and were a larger and improved version of his Richmond class of 1878. Thirty-six locomotives were turned out from Brighton railway works between 1882 and 1891 and were used for the heaviest London to Brighton express trains. All were named after politicians, men associated with the railway, or places served by the railway.

The locomotives were originally designated "Class B" together with the "Richmond Class" but were later designated B1 class by D. E. Marsh. The first of the class, 214 Gladstone, was preserved as a static exhibit thanks to the efforts of the Stephenson Locomotive Society and is the only ex LB&SCR tender locomotive to be preserved, as all the other preserved locomotives (ten A1/A1x "Terriers", one E1, and an E4) are tank engines.