Alonso III Fonseca
| Alfonso de Fonseca y Ulloa | |
|---|---|
| Archbishop of Toledo Primate of Spain | |
| Portrait by Plácido Fernández Arosa in the University of Santiago de Compostela (1817) | |
| Church | Roman Catholic | 
| Archdiocese | Toledo | 
| Appointed | 31 December 1523 | 
| Term ended | 4 February 1534 | 
| Predecessor | Guillaume de Croÿ | 
| Successor | Juan Pardo de Tavera | 
| Previous post(s) | Archbishop of Santiago de Compostela (1507–23) | 
| Personal details | |
| Born | c. 1475 | 
| Died | 4 February 1534 (aged c. 59) Alcalá de Henares | 
Alonso III Fonseca (c. 1475 – 4 February 1534) was a Galician archbishop and politician. He was Archbishop of Santiago de Compostela from 1507, and Archbishop of Toledo from 1523. He was a major supporter of the University of Santiago de Compostela.