Konstantin Sergeyevich Aksakov (Russian: Константин Сергеевич Аксаков) (1817 – 1860) was a Russian critic and writer, one of the earliest and most notable Slavophiles. He wrote plays, social criticism, and histories of the ancient Russian social order. His father Sergey Aksakov was a writer, and his younger brother Ivan Aksakov was a journalist.

Konstantin was the first to publish an analysis of Gogol's Dead Souls, comparing the Russian author with Homer (1842). After Tsar Alexander II's accession to the throne, he sent him a letter advising to restore Zemsky sobors (1855). Aksakov also penned a number of articles on Slavonic linguistics.

Aksakov was raised on a country estate before moving to Moscow with his family. He remained with his parents his entire life, never marrying or moving out of the house. He studied at Moscow State University, becoming a member of the Stankevitch circle, a group of Russian Hegelians and early forerunners of Russian Democracy.

Aksakov eventually made the acquaintance of Ivan Kireevsky and Aleksey Khomyakov, adopted their philosophy of Slavophilism, and broke off all contact with the Stankevitch circle.

Aksakov's thesis on Lomonosov (1846) attempted to synthesize his view of the Russian peasant's religious and historical mission with Hegel's philosophy. Later in his career, Akasakov abandoned Hegelian philosophy, becoming radically anti - European.