Constance was a daughter of Béla III of Hungary and his first wife Agnes of Antioch. Her older siblings included Emeric of Hungary, Margaret of Hungary and Andrew II of Hungary. Two other siblings, Solomon and Stephen, are mentioned in the "Europäische Stammtafeln: Stammtafeln zur Geschichte der Europäischen Staaten" (1878) by Detlev Schwennicke. They reportedly died young.
Constance is regularly noted as a co-donator with her husband in various documents of his reign. Her petitions to her husband for various donations are also recorded. She is considered to have sold the city Boleráz to her nephew Béla IV of Hungary. In 1247, Béla conferred said city to the nuns of Trnava. An epistle by which Constance supposedly grants freedom to the cities of Břeclav and Olomouc is considered a false document. The same epistle grants lands in Ostrovany to the monastery of St. Stephen of Hradište. Another epistle has Constance settling "honorable Teutonic men" (viros honestos Theutunicos) in the city of Hodonín and is also considered a forgery. On 15 January, 1230, Ottokar I died and their son Wenceslaus succeeded him. Constance survived her husband by a decade.
In 1231, Pope Gregory IX set Constance and her dowry possessions under the protection of the Holy See. His letter to Constance clarifies said possessions to include the provinces of Břeclav (Brecyzlaviensem), Pribyslavice (Pribizlavensem), Dolni Kunice (Conowizensem), Godens (Godeninensem), Bzenec (Bisenzensem) and Budějovice (Budegewizensem). In 1232, Constance founded Cloister Tichnowitz and retired to it as a nun. She died within the Cloister.