Isidor Emmanuilovich Gukovsky (Russian: Исидор Эммануилович Гуковский 1871–1921) was the People's Commissar of Finance following the Russian Revolution.
Isidor was the son of a merchant, who became a chemist's assistant. In 1898, he started participating in the Group of Workers Revolutionaries. He later became a Menshevik.He was imprisoned for inciting the Izhorskiye workers to strike. In 1904 he went to Baku, and used the name Theodor Izmaylovich for his political work. By 1906 he was secretary of the newspaper New Life. He then went to Odessa before travelling abroad. In 1907, he returned to Russia, was arrested, again brought to trial but acquitted (1908). He settled in Moscow. After the October Revolution he became a Bolshevik and was appointed finance minister, then plenipotentiary representative of Russia in Estonia. In autumn 1921, he died of pneumonia.