George of Lencastre
Coat of arms of Lencastre dukes of Aveiro
2nd Duke of Aveiro
Reign	1571 - 1578
Predecessor	João
Successor	Alvaro and Juliana
Born	1548
Died	1578
Spouse	Madalena Girón
Issue	Juliana, 3rd Duchess of Aveiro
House	House of Aviz
Father	João, 1st Duke of Alveiro
Mother	Juliana de Lara

Jorge de Lencastre, or George of Lencastre (1548–1578), was the older son of Dom John of Lencastre, 1st Duke of Aveiro and of his wife Juliana de Lara, daughter of the 3rd Marquis of Vila Real.

Until his father's death, he used the title of Marquis of Torres Novas, and also succeeded him as 2nd Duke of Aveiro in 1571.

He was a close adviser to King Sebastian I of Portugal and he escorted him, both to the Guadalupe interview (where Sebastian met his uncle, King Philip II of Spain) and to the Portuguese campaign to Morocco. George was killed in the Battle of Alcácer Quibir, together with the King, in 1578.

Before, he had married Madalena Girón, sister of the Spanish 1st Duke of Ossuna, from whom he had a single daughter:

• Juliana of Lencastre, 3rd Duchess of Aveiro, married to Álvaro of Lencastre, 3rd Duke of Aveiro.