| Mariano Melgar | |
| Native Name Lang: | es |
| Settlement Type: | District |
| Mapsize: | frameless |
| Subdivision Type: | Country |
| Subdivision Name: |  Peru |
| Subdivision Type1: | Region |
| Subdivision Name1: | Arequipa |
| Subdivision Type2: | Province |
| Subdivision Name2: | Arequipa |
| Parts Type: | Subdivisions |
| Parts Style: | para |
| P1: | 1 populated center |
| Established Title: | Founded |
| Established Date: | August 27, 2007 |
| Seat Type: | Capital |
| Seat: | Mariano Melgar |
| Leader Title: | Mayor |
| Leader Name: | Oscar Alfredo Ayala Arenas |
| Unit Pref: | Metric |
| Area Total Km2: | 29.83 |
| Elevation M: | 2385 |
| Population Total: | 53303 |
| Population As Of: | 2005 census |
| Population Density Km2: | auto |
| Timezone1: | PET |
| Utc Offset1: | -5 |
| Blank Name Sec1: | UBIGEO |
| Blank Info Sec1: | 040109 |
| Website: | munimarianomelgar.gob.pe |
Mariano Melgar District is one of the twenty-nine districts of the Arequipa Province in Peru.[1]