Semen Nikolaevich Korsakov (Russian: Семён Николаевич Корсаков; Semyon Nikolayevich Korsakov) (January 14, 1787 – December 1, 1853 OS) was a Russian government official, noted both as a homeopath and an inventor who was involved with an early version of information technology.
Korsakov was born in 1787 in what is now Kherson, Ukraine (then part of the Russian empire). His father was a military engineer. The family had migrated from Lithuania in the 14th century.
He was married to Sofia Mordvinova and they had four daughters and six sons, one of whom, Mikhail Semyonovich (Russian: Михаил Семёнович Корсаков; Mikhail Semyonovich Korsakov) (1826–1871), became famous in his own right as governor-general of Eastern Siberia and was the namesake of the town of Korsakov in Sakhalin Oblast and several Russian geological features.
From 1812 to 1814, Semen Korsakov took part in the Napoleonic Wars with the Russian Army. He later was to serve as an official in the statistics department of the Russian Police Ministry in St. Petersburg. He was a recipient of the Order of St. Anna and the Order of St. Vladimir.
Korsakov died in 1853 in the village of Tarusovo, then part of the Moscow Province.
Though Korsakov was not formally trained as a doctor, he was interested in medicine, possibly because of the difficulty in getting medical care in the rural area where he lived. According to his journals he treated several thousand patients, at first using conventional medicine, but in 1829 switching to homeopathy at the urging of his relatives.