Illarion Illarionovich Vasilchikov (1805 – 12 November 1862) was an Imperial Russian general and the great grandson of emperor Alexander I of Russia.

He was the son of Illarion Vasilyevich Vasilchikov and Vera Vasilchikova.

One of his daughters married Alexander Meyendorf.

He is buried at Kiev Pechersk Lavra in Ukraine.

This biographical article related to the Russian military is a stub.