| John George, Marquis of Montferrat | |
| Succession: | Marquis of Montferrat |
| Reign: | 1530–1533 |
| Predecessor: | Boniface IV of Montferrat |
| Successor: | Margaret Palaiologina |
| Noble Family: | Palaeologus-Montferrat |
| Father: | Boniface III, Marquis of Montferrat |
| Mother: | Maria of Serbia |
| Spouse: | Julia Trastamara of Naples |
| Birth Date: | 20 January 1488 |
| Birth Place: | Casale Monferrato |
| Death Place: | Casale Monferrato |
John George of Monferrat (20 January 1488 – 30 April 1533) was the last Marquis of Montferrat of the Palaeologus-Montferrat family.
He was a son of Boniface III, Marquis of Montferrat and his third wife Maria of Serbia, daughter of Stefan Branković, Despot of Serbia and Angelina Arianiti, an Albanian princess.
John George was Bishop of Casale when his nephew Boniface IV, Marquis of Montferrat unexpectedly died in 1530 without an heir.
As the last of his family and despite his poor health, John George had no option but to become the new Marquis. In a desperate attempt to produce an heir, he married the 41-year-old Julia, daughter of Frederick IV of Naples, on 21 April 1533. He died 9 days later.
After a Spanish occupation of 3 years, Montferrat came under Federico II Gonzaga, Duke of Mantua, who had married his niece Margaret Paleologa in 1531.
John George had an illegitimate son, Flaminio, from whom the Paleologo-Oriundi line descends and is extant today.[1]