Yakov Sannikov (Russian: Яков Санников) (1780, Ust-Yansk - no earlier than 1812) was a Russian merchant and explorer of the New Siberian Islands.
In 1800, Sannikov discovered and charted Stolbovoy Island, and in 1805 Faddeyevsky Island. In 1809-1810, he took part in the expedition led by Matvei Gedenschtrom. In 1810, Sannikov crossed the island of New Siberia and a year later explored Faddeyevsky Island. He also discovered Bunge Land.
He suggested that there was a vast land north of the Kotelny Island. This hypothetical island has become known as Sannikov Land.
A strait between Maly Lyakhovsky and Kotelny islands bears Sannikov's name.