Jacopo III Appiano, VI Lord of Piombino (1439 - 10 March 1474) was an Italian nobleman.

Iacopo Appiano was born in 1439 in Piombino, son of Emanuele Appiano, Lord of Piombino, and Colia de' Giudici, natural daughter of Alfonso V of Aragon, King of Naples.

[3] Despite the economic difficulties, he tried to show himself as a patron of the arts, in particular, he hired the architect and sculptor Andrea Guardi, to whom he commissioned many works between 1465 and 1470: the construction of the Citadel to replace Appiano Palace, the Appiano chapel, a series of hydraulic works and the cloister with baptismal font of Sant'Antimo.

[3] Of poor health, in 1463 he fell ill with quartan fever, recovering from it (also thanks to the sending from Siena of renowned doctors such as Bartolo di Tura Bandini) but without ever fully recovering.

[4] Iacopo III Appiano died on 10 March 1474, in Piombino, due to the consequences of malaria.