Helena of Serbia (Serbian: Јелена/Jelena, Hungarian: Ilona; b. after 1109 – after 1146) was Queen of Hungary and Croatia as the wife of King Béla II.

After her husband's death, she governed Hungary as regent from 1141 to September 1146 together with her brother, Beloš, during the minority of her eldest son, Géza II, came of age.

[2] The Hungarian Army had destroyed Byzantine Belgrade and penetrated to Naissos (Niš), Serdica (Sofia) and Philippopolis (Plovdiv).

Helena continued to hold great influence on the rule and with the help of her brother Hungary had good relations and peace on its southern borders.

[1] In the period of Bela's death, the German-Hungarian relations had been shattered and the engagement of Henric and Sophia, Helena's daughter, was canceled.

The plots against Géza II had no success, and after his death (1161) Manuel I Komnenos saw a good opportunity to expand Byzantine influence in Hungary.