Jeremias I of Constantinople was a 16th-century prelate who served as the Ecumenical Patriarch during two separate periods. Born in Zitsa around 1485, he rose through the ecclesiastical ranks to become the Archbishop of Sofia before his first election to the patriarchate in 1522. His leadership was marked by significant political and religious challenges within the Ottoman Empire, including a temporary deposition and a successful effort to protect Christian churches from being converted into mosques.