Smilets (Bulgarian: Смилец) reigned as emperor (tsar) of Bulgaria from 1292 to 1298. The date of his birth is unknown.
Before ascending the throne in 1292, Smilec had married an unnamed Byzantine princess, the daughter of the sebastokratōr Constantine Palaiologos, a half-brother of Emperor Michael VIII Palaiologos. Apart from the information that Smilec became emperor of Bulgaria according to the wishes of Nogai Khan, we know nothing of the circumstances of Smilets's accession. Accordingly, the reign of Smilec has been considered the height of Mongol overlordship in Bulgaria. Nevertheless, Mongol raids may have continued, as in 1297 and 1298. Since these raids pillaged parts of Thrace (then entirely in Byzantine hands), perhaps Bulgaria was not one of their objectives. In fact, in spite of the usually pro-Byzantine policy of Nogai, Smilets was quickly involved in an unsuccessful war against the Byzantine Empire at the beginning of his reign.
About 1296/1297 Smilets married his daughter Theodora to the future Serbian King Stefan Uroš III Dečanski, and this union produced the Serbian king and later emperor Stefan Uroš IV Dušan.
In 1298 Smilets disappears from the pages of history, apparently after the beginning of Chaka's invasion. He may have been killed by Chaka or died of natural causes while the enemy advanced against him. Smilets was briefly succeeded by his young son Ivan II.