| Attica | |
| Native Name: | Greek, Modern (1453-);: Περιφέρεια Αττικής |
| Coordinates: | 38°N 23.7°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Greece |
| Subdivision Type1: | Decentralized Administration |
| Subdivision Name1: | Attica |
| Seat Type: | Capital |
| Seat: | Athens |
| Parts Type: | Regional units |
| Parts Style: | list |
| P1: | Central Athens |
| Leader Title: | Regional Governor |
| Government Type: | Regional council |
| Area Total Km2: | 3808.1 |
| Population Total: | 3814064 |
| Population As Of: | 2021 |
| Population Footnotes: | [1] |
| Population Density Km2: | auto |
| Demographics Type2: | GDP |
| Demographics2 Title1: | Total |
| Demographics2 Info1: | €85.769 billion (2021) |
| Blank Name Sec1: | NUTS code |
| Blank Info Sec1: | EL3 |
| Blank Name Sec2: | HDI (2021) |
| Blank Info Sec2: | 0.909[2] · 1st of 13 |
| Iso Code: | GR-I |
| Type: | Administrative region |
| P2: | North Athens |
| P3: | West Athens |
| P4: | South Athens |
| P5: | Piraeus |
| P6: | East Attica |
| P7: | West Attica |
| P8: | Islands |
| Timezone: | EET |
| Utc Offset: | +2 |
| Timezone Dst: | EEST |
| Utc Offset Dst: | +3 |
Attica (; Greek, Modern (1453-);: Περιφέρεια Αττικής|translit=Periféria Attikís, in Greek, Modern (1453-); pronounced as /periˈferi.a atiˈcis/) is an administrative region of Greece, that encompasses the entire Athens metropolitan area, the core city of which is the country's capital and largest city, Athens. The region is coextensive with the former Attica Prefecture of Central Greece and covers a greater area than the historical region of Attica.
Located on the eastern edge of Central Greece, Attica covers about 3,808 square kilometres. In addition to Athens, it contains within its area the cities of Elefsina, Megara, Laurium, and Marathon, as well as a small part of the Peloponnese peninsula and the islands of Salamis, Aegina, Angistri, Poros, Hydra, Spetses, Kythira, and Antikythera. About 3,800,000 people live in the region, of whom more than 95% are inhabitants of the Athens metropolitan area. In 2019, Attica had the HDI of 0.912, the highest in Greece.
The region was established in the 1987 administrative reform, and until 2010 it comprised the 4 prefectures of Athens, East Attica, Piraeus and West Attica.
With the 2010 Kallikratis plan, the region's powers and authority were completely redefined and extended. Since 1 January 2011, the region represents the second-level local administration. While being supervised by the Decentralized Administration of Attica, it is now an independent self-governing body with powers and a budget comparable to the former prefectures.
The region is subdivided into eight subordinate regional units:[3]
The Attica region consists of eight electoral districts: Athens A, Athens B1, Athens B2, Athens B3, Piraeus A, Piraeus B, East Attica and West Attica.
The region has shrunk by 35,965 people between 2011 and 2021, experiencing a population loss of 0.9%.[1]
The Gross domestic product (GDP) of the region was 87.4 billion € in 2018, accounting for about 47% of the Greek economic output. GDP per capita adjusted for purchasing power was 28,000 € or 93% of the EU27 average in the same year. The GDP per employee was 99% of the EU average. Attica is the region in Greece with the highest GDP per capita.[4] Despite that, the unemployment rate stood at 21.6% in 2017.[5]
The main roads and highways of Attica are:
Numerous ferry lines, both normal ferries and high speed vessels, connect the port of Piraeus, with the islands of the region.