Stefan Crnojević (Serbian Cyrillic: Стефан Црнојевић), known as Stefanica (Стефаница) was the Lord of Zeta between 1451 and 1465. Until 1441, he was one of many governors in Zeta, which at that time was a province of the Serbian Despotate. He then aligned with Stefan Vukčić Kosača and remained his vassal until 1444 when he accepted Venetian suzerainty. In Venetian-held Lezhë, on 2 March 1444, Stefan and his sons forged an alliance with several noblemen from Albania, led by Skanderbeg, known as the League of Lezhë. In 1448 he returned under the suzerainty of the Serbian Despot Đurađ Branković. In 1451, Stefan took over the leadership of the Crnojevići and became the ruler of a large part of Zeta, hence Gospodar Zetski.
After the disappearance of Stefan's brother Gojčin Crnojević from political life in 1451, Stefan took over the leadership of the house of Crnojević and became the ruler of a large part of Zeta. Stefan was never good with his brothers and always led politics on his own. To strengthen his position, he decided to immediately seek foreign protection. In 1452 he allied himself with Venice and recognized its authority over the region and was subsequently entitled Duke of Upper Zeta. The reasons of the alliance are related to his anticipation of the downfall of the Serbian Despot.
In 1455 the Ottomans invaded Serbia and conquered all of its territories south of the Western Morava river, completely cutting Zeta off from the core of the Despotate. Therefore, Duke Stefan Crnojević along with representatives from all 51 municipalities from Upper Zeta signed an agreement the same year with the Venetians in Vranjina, by which Upper Zeta accepted Venetian rule. Venice came to rule only the cities, while all internal affairs were left to duke Stefan. The Republic of Venice also bound itself not to interfere with the ecclesiastical authority Serbian Orthodox Metropolitan of Zeta in any way. Montenegro slowly became the name of Stefan's Zetan realm. He reigned peacefully without the intervention of Venice and the Ottomans until his death in late 1464 or the beginning of 1465, when his son Ivan succeeded him.