Theodora of Bulgaria (Bulgarian and Serbian: Теодора) was a Bulgarian princess and Queen consort of Serbia, the first wife of Stefan Uroš III Dečanski. She was the second daughter of Smilets and Smiltsena Palaiologina.
Teodora married Serbian crown prince (later king) Stefan Uroš III (called Dečanski) on 24 August 1296. They had two children: future Emperor Stefan Dušan and Dušica.
In 1314 her husband's father Stefan Milutin quarreled with Stefan, and sent him to Constantinople to be blinded. Teodora and the family went with him and established a household there until 1320 when they were allowed to return.
She was present at the state assembly of 6 January 1322, when her son Dušan was crowned Young king. In this period, Dečanski and Teodora were divorced. It is very likely that, between the death of Milutin (29 October 1321) and the crowning of Dušan, it was decided that Teodora be divorced from her husband due to the fact that Teodora's father's family had by then been expelled from Bulgaria, and Dečanski sought to empower himself by marrying into the Byzantine royal family. He then married Maria Palaiologina.
It is still unknown when Teodora died. She was alive on 6 January 1322, and according to M. Vukićević and S. Ćosović died prior to January 1323. Historian Stojan Novaković earlier based the death in the winter of 1322–23 on the talks of Dečanski marrying Phillip of Tarento in the beginning of 1323. Other believe she lived longer, possibly marrying Jovan Dragoslav between 1322 and 1326. It is believed she was buried in the Banjska monastery.