Alexander Nikolayevich Ostrovsky (April 12 [O.S. March 31], 1823, Moscow, Russian Empire – June 14 [O.S. June 2], 1886, Shchelykovo, Kostroma Governorate, Russian Empire) is a Russian playwright, generally considered the greatest representative of the Russian realistic period.

The author of forty-seven original plays, Ostrovsky'si dramas are among the most widely read and frequently performed stage pieces in Russia.