John Aleman (died after 1264) was the Lord of Caesarea (as John II) in the Kingdom of Jerusalem, exercising this right through his wife, Margaret, from at least 1243 until his death. He was the son of Garnier l'Aleman and Pavie de Gibelet, and the older brother of Hugh Aleman. John was active politically and militarily, although less influential than the previous lords of Caesarea had been. His maternal grandmother was Stephanie of Milly.
The first reference to John as lord of Caesarea comes in the Assizes of Jerusalem of John of Ibelin. Therein John writes that his cousin, the lord of Caesarea, refused the bailliage (regency) of the kingdom in 1243, and instead the Haute Cour gave it to Queen Alice of Cyprus. Since his father-in-law, Lord John of Caesarea, was dead, this is probably a reference to Aleman.
In April 1249 he and his wife sold six casalia near Acre to the Teutonic Knights. This included two—Seisor and Mergelcolon and Gedin—that he had inherited from his mother, and Beit Jann and Nahf. In 1253 they sold Al-Damun (and several villages in the vicinity) near Acre to the Hospitallers for 12,000 besants. In 1255 they also sold the Hospitallers everything they owned in Acre as well as the casalia of Chasteillon and Rout. On this occasion they were accepted into the lay confraternity of the order as confrater and consoror. Some of the money from the sales to the Hospitallers was used to pay the dower of John's brother Hugh's wife, Isabelle de Tenremonde, of the family of the lords of Adelon. She confirmed the payment of part of her dower in an act of 1259.