| Mačva District | |
| Native Name: | Мачвански округ Mačvanski okrug |
| Settlement Type: | District of Serbia |
| Mapsize: | 200px |
| Subdivision Type: | Country |
| Subdivision Name: |  Serbia |
| Subdivision Type1: | Region |
| Subdivision Name1: | Šumadija and Western Serbia |
| Seat Type: | Administrative center |
| Seat: | Šabac |
| Leader Title: | Commissioner |
| Leader Name: | Dragoslav Milanović |
| Total Type: | Total |
| Area Total Km2: | 3,268 |
| Population Total: | 268,096 |
| Population As Of: | 2021 census |
| Population Density Km2: | 82 |
| Blank Name Sec1: | Municipalities |
| Blank Info Sec1: | 6 and 2 cities |
| Blank1 Name Sec1: | Settlements |
| Blank1 Info Sec1: | 228 |
| Blank2 Name Sec1: | - Cities and towns |
| Blank2 Info Sec1: | 5 |
| Blank3 Name Sec1: | - Villages |
| Blank3 Info Sec1: | 223 |
| Iso Code: | RS-08 |
The Mačva District (sr|{{lang|sr-Cyrl|Мачвански округ, pronounced as /sh/) is one of eight administrative districts of Šumadija and Western Serbia. It expands in the western parts of Serbia, in the geographical regions of Mačva, Podrinje, Posavina, and Pocerina. According to the 2011 census results, it has a population of 298,931 inhabitants. The administrative center of the Mačva district is the city of Šabac.
Famous monuments can be seen in the vicinity of Šabac, dedicated to events from the history of Serbian people: the Monument to Karađorđe and Serbian Heroes of the First Serbian Uprising and the Museum of the Battle of Mišar, the remnants of the ancient cities on the banks of the Sava river: Novo Selo, the site of the King Milutin's Palace and Kosanin grad, the medieval fortress on the Cer Mountain.
Not far away from Loznica stands the village of Tršić, the birthplace of the reformer of Serbian language and orthography, Vuk Karadžić. From Tršić, a footpath leads to the Tronoša Monastery, one of the oldest medieval endowments of the Nemanjić dynasty. This fourteenth-century monastery played an important part in the preservation of Serbian culture and tradition. Over a long period, particularly during the fourteenth century, a copying school tradition was nourished in it for its own and other monasteries' needs. This preserved the historic and cultural documents of the Serbian people.
The district encompasses the cities of Šabac and Loznica and municipalities of:
According to the last official census, which was performed in 2011, the Маčva District has 298,931 inhabitants, while 29.14% of the population lives in urban areas.
Ethnic composition of the Mačva district:
| Ethnic group | Population | % | |
|---|---|---|---|
| Serbs | 284,165 | 95.06% | |
| Romani | 4,537 | 1.52% | |
| Muslims | 1,501 | 0.50% | |
| Croats | 327 | 0.11% | |
| Bosniaks | 271 | 0.09% | |
| Yugoslavs | 261 | 0.09% | |
| Montenegrins | 185 | 0.06% | |
| Macedonians | 150 | 0.05% | |
| Hungarians | 108 | 0.04% | |
| Others | 7,426 | 2.48% | |
| Total | 298,931 |
Note: All official material made by Government of Serbia is public by law. Information was taken from .