Dušan Popović (1 October 1877 – 25 June 1958) was a lawyer and politician in Croatia. He was a leading member of the Croat-Serb coalition in the Croatian Parliament and a delegate to the Hungarian House of Representatives.
The son of a lawyer, Stevan Popović (1839–1912), by his marriage to Milica Bela Nikolajević, Popović was born in Ruma, in the Srem District of the Vojvodina, educated at a high school in Osijek, then studied law in Zagreb. His first job was as a trainee in the law office of Vasa Đurđević and he completed his articles with the attorney Dr Aleksandar Roknić in Sremska Mitrovica, in his native Vojvodina. In 1904 he established his own law practice and soon became politically active, drawn to the ideas of the Croat-Serb Coalition. In 1906 he was first elected to the Parliament of the Kingdom of Croatia-Slavonia, standing for the coalition in the electoral district of Morović in Syrmia. He continued to be elected from Morović and Sremska Mitrovica until the election of 1913. He made a name as a defense attorney in political trials aimed at destroying the Croat-Serb coalition. In 1908 he defended Serbs accused in Zagreb, showing that their indictment was based on a false interpretation of history. He was a defence counsel, with Thomas Masaryk, in the notable Friedjung trial of 1909, in which Heinrich Friedjung had tried to discredit the Croatian leader Frano Supilo by accusing him of working for Serbia. This ended in the collapse of a state indictment based on false documents and created a scandal for the Austrian empire, damaging the international reputation of its legal system. In 1910 Popović came to public attention again as defense counsel in the trial in Zagreb of Srđan Budisavljević, Laze Popović, Milan Metikoš, Milan Todorović, and Đorđe Gavrilović.