The LB&SCR A1 class is a class of British 0-6-0T steam locomotive. Designed by William Stroudley, 50 members of the class were built in 1872 and between 1874 and 1880, all at Brighton railway works. The class has received several nicknames, initially being known as "Rooters" by their south London crews. However, the engines were more famously known as "Terriers" on account of the distinctive 'bark' of the exhaust beat.

Eight members of the class were purchased privately for preservation, with two other examples being donated by British Railways to the Canadian Railway Museum and the National Railway Museum.