Nestor Vasilievich Kukolnik (Russian: Не́стор Васи́льевич Ку́кольник) (1809–1868) was a Russian playwright and prose writer of Carpatho-Rusyn origin. Immensely popular during the early part of his career, his works were subsequently dismissed as sententious and sentimental. Today, he is best remembered for having contributed to the libretto of the first Russian opera, A Life for the Tsar by Mikhail Glinka. Glinka also set many of his lyrics to music.