| Peloponnese | |
| Type: | Administrative region |
| Native Name: | Greek, Modern (1453-);: Περιφέρεια Πελοποννήσου |
| Coordinates: | 37.4°N 22.3°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Greece |
| Subdivision Type1: | Decentralized Administration |
| Subdivision Name1: | Peloponnese, Western Greece and the Ionian |
| Leader Title: | Regional governor |
| Parts Type: | Regional units |
| Parts Style: | list |
| P1: | Arcadia |
| P2: | Argolis |
| P3: | Corinthia |
| P4: | Laconia |
| Seat Type: | Capital |
| Seat: | Tripoli |
| Seat1 Type: | Largest city |
| Seat1: | Kalamata |
| Area Total Km2: | 15489.96 |
| Population Total: | 538366 |
| Population As Of: | 2021 |
| Population Density Km2: | auto |
| Population Demonym: | Peloponnesian |
| Population Footnotes: | [1] |
| Demographics Type2: | GDP |
| Demographics2 Title1: | Total |
| Demographics2 Info1: | €8.448 billion (2021) |
| Timezone: | EET |
| Utc Offset: | +2 |
| Timezone Dst: | EEST |
| Utc Offset Dst: | +3 |
| Iso Code: | GR-J |
| Blank Name Sec2: | HDI (2019) |
| Blank Info Sec2: | 0.849[2] · 11th of 13 |
The Peloponnese Region (Greek, Modern (1453-);: Περιφέρεια Πελοποννήσου|translit=Periféria Peloponnísou, in Greek, Modern (1453-); pronounced as /periˈferia pelopoˈnisu/) is a region in southern Greece. It borders Western Greece to the north and Attica to the north-east. The region has an area of about 15490km2. It covers most of the Peloponnese peninsula, except for the northwestern subregions of Achaea and Elis which belong to Western Greece and a small portion of the Argolid peninsula that is part of Attica.
The Peloponnese Region was established in the 1987 administrative reform. With the 2011 Kallikratis plan, its powers and authority were redefined and extended. Along with the Western Greece and Ionian Islands regions, it is supervised by the Decentralized Administration of Peloponnese, Western Greece and the Ionian Islands based at Patras.
The region is based at Tripoli and is divided into five regional units (pre-Kallikratis prefectures),
which are further subdivided into 26 municipalities. The largest city of the region is Kalamata.
The region has shrunk by 41,537 people between 2011 and 2021, experiencing a population loss of 6.8%.[1]
The Gross domestic product (GDP) of the region was 8.2 billion € in 2018, accounting for 4.5% of Greek economic output. GDP per capita adjusted for purchasing power was 17,400 € or 57% of the EU27 average in the same year. The GDP per employee was 68% of the EU average.[3]