Croydon, outer borough (1991 pop. 299,600) of Greater London, SE England. It is London's second largest shopping and cultural center after West End. London's first airport, the Croydon Aerodrome, was constructed there in 1915 but closed in 1959 after Heathrow was built. Scientific instruments, internal-combustion engines, and electronic equipment are manufactured, but Croydon is largely residential. Several office buildings have been constructed in the borough, which also has a technical college and a college of art.