Maria of Montferrat (1192–1212) was the queen of Jerusalem from 1205 until her death. Her parents were Isabella I and her second husband, Conrad of Montferrat. Maria succeeded her mother under the regency of her half-uncle John of Ibelin. After him the kingdom was ruled on Maria's behalf by her husband, John of Brienne, whom she married in 1210. She died giving birth to her successor, Isabella II.