Sergei Illarionovich Vasilchikov (9 September 1849 – 27 August 1926) was an Imperial Russian division commander.He was born in Kiev in modern-day Ukraine.

He was the son of Imperial Russian general Illarion Illarionovich Vasilchikov.

He fought in the war against the Ottoman Empire.

He was the father of Hilarion Vassilchikov.

After the October Revolution, he went into exile.