Mark Veniaminovich Vishniak (Russian: Марк Вениами́нович Вишня́к; 1883–1976) was an American socialist, journalist and writer, working for Time Magazine.

As a law student at Moscow University he came in contact with Narodnik circles, but he did not join the Socialist-Revolutionary Party (PSR) until 1905, when he was radicalised by the Revolution of 1905.

He belonged to the Interim Council of the Republic (Pre-Parliament) and was elected to the short-lived Constituent Assembly (which the Bolsheviks suspended after one day).

In 1918 he moved to Ukraine, where he fell foul of the government of Herman Skoropadski and was arrested.

He attended the Paris Peace Conference in 1919 as a delegate for the Jewish people and had become a supporter of socialist Zionism.

He contributed to several émigré journals, including Sovremennye zapiski (Contemporary Annals) and the Evreiskaia Tribuna (the Jewish Tribune).

[citation needed] Vishniak wrote prolifically on the history of the Russian Revolution, Bolshevism and Soviet policy, his memoirs, the Jewish community, etc.