Aleksa Dundić (real name Toma, but also known under his pseudonyms Ivan, Alejo, Aleksa, and, in literature, as Oleko or Red Dundich; April 13, 1896 - July 8, 1920) was a Croatian communist, a prominent participant in Russia's October Revolution. A popular character in Russian literature (celebrated for his riding skills and courage), Dundić was the only person from Croatia to be honoured with the Order of the Red Banner.

The Great Soviet Encyclopedia and other sources call Dundić Croatian. Some other sources, e.g. the Soviet Historical Encyclopedia call him Serbian.

Dundić, Toma (also called himself Ivan, in literature - Oleko), born April 13, 1896 (August 12, 1897 by other data) in the village of Grabovac, near Šestanovac in Dalmatia, Austrian Empire (now Croatia) died on the 8th of July, 1920 by Rovno, Ukraine. Dundić was a hero of Russian Civil War.