The Birmingham Small Arms Company Limited (BSA) was a major British industrial combine, a group of businesses manufacturing military and sporting firearms; bicycles; motorcycles; cars; buses and bodies; steel; iron castings; hand, power, and machine tools; coal cleaning and handling plants; sintered metals; and hard chrome process.

After the Second World War, BSA did not manage its business well, and a government-organised rescue operation in 1973 led to a takeover of such operations as it still owned. Those few that survived this process disappeared into the ownership of other businesses.