| Diomedio Villanueva | |
| Office: | Postmaster General |
| Office1: | Chief of Staff of the Armed Forces of the Philippines |
| Office2: | Commanding General of the Philippine Army |
| Office4: | Commander of AFP Southern Command |
| Office3: | Commander of AFP South Luzon Command |
| Term Start1: | March 17, 2001 |
| Term End1: | May 18, 2002 |
| Termstart2: | 2000 |
| Termend2: | 2001 |
| Termstart4: | 1999 |
| Termend4: | March 16, 2000 |
| Termstart3: | May 1, 2000 |
| Termend3: | October 22, 2000 |
| President1: | Gloria Macapagal-Arroyo |
| President2: | Joseph Ejercito Estrada |
| President3: | Joseph Ejercito Estrada |
| Successor1: | Roy Cimatu |
| Successor2: | Jaime de los Santos |
| Successor3: | Ernesto Carolina |
| Predecessor1: | Angelo Reyes |
| Predecessor2: | Angelo Reyes |
| Allegiance: | Philippines |
| Serviceyears: | 1968 - 2002 |
| Occupation: | Soldier |
| Profession: | Soldier |
| Battles: | Anti-Communist Campaign All Out war with MILF (2000) Anti-Terrorism Campaign (1999) |
| Death Place: | Libingan ng mga Bayani |
| Resting Place Coordinates: | Libingan ng mga Bayani, Fort Bonifacio, Taguig |
| Education: | Bachelor of Science Degree |
| Alma Mater: | Philippine Military Academy (1968) |
| President4: | Joseph Ejercito Estrada |
| President: | Gloria Macapagal-Arroyo |
| Vicepresident1: | Teofisto Guingona Jr. |
| Vicepresident2: | Gloria Macapagal-Arroyo |
| Successor4: | Gregorio Camiling |
| Predecessor4: | Edgardo Espinosa |
| Term Start: | 2003 |
| Term End: | 2010 |
| Vicepresident: | Noli De Castro Teofisto Guingona |
| Unit: | 1st Infantry Division |
| Commands: | Armed Forces of the Philippines Philippine Army South Luzon Command Southern Command 1st Infantry Division |
Diomedio Villanueva was retired Philippine Army General who served as Chief of Staff of the Armed Forces of the Philippines in 2001 - 2002. He succeeded General Angelo Reyes who was appointed as Secretary of National Defense upon his mandatory retirement.