Piraeus Prefecture

{{Refimprove|date=January 2025}}{{Infobox settlement

| name = Piraeus

| native_name = Νομός Πειραιά

| native_name_lang =

| settlement_type = Former prefecture

| image_skyline =

| image_caption =

| image_flag =

| image_seal =

| image_shield =

| image_map = Nomarchia Pirea.png

| map_caption = Location of Piraeus in Greece

| image_map1 = Pireas nomarchia municipalities numbered.png

| map_caption1 = Location of municipalities within Piraeus Prefecture

| coordinates =

| subdivision_type = Country

| subdivision_name = Greece

| subdivision_type1 = Periphery

| subdivision_name1 = Attica

| parts_type = Subdivisions

| p1 = 5 provinces

| p2 = 16 municipalities

| p3 = 2 communities

| established_title = Established

| established_date = 1972

| extinct_title = Disestablished

| extinct_date = 2010

| seat_type = Capital

| seat = Piraeus

| government_footnotes =

| leader_party =

| leader_title =

| leader_name =

| unit_pref = Metric

| area_footnotes =

| area_total_km2 = 929

| area_rank = 47th

| elevation_footnotes =

| elevation_m =

| population_footnotes =

| population_total = 541504

| population_as_of = 2001

| population_density_km2 = auto

| population_density_rank = 2nd

| population_demonym =

| population_note =

| population_rank = 3rd

| timezone1 =

| utc_offset1 =

| timezone1_DST =

| utc_offset1_DST =

| postal_code_type = Postal codes

| postal_code = 1xx xx, 801 xx

| area_code_type = Area codes

| area_code = 21x, 2736

| iso_code = GR-A4

| registration_plate = ΥΝ

| website = [http://www.nomarhiapeiraia.gr/ nomarhiapeiraia.gr]

| footnotes =

}}

Piraeus Prefecture ({{langx|el|Νομός Πειραιά or Νομός Πειραιώς}}) was one of the prefectures of Greece. Created in 1964 as a separate Prefecture (Νομός) and after the dissolution of the prefecture in 1972 was one of the 4 prefectures (Νομαρχίες) of Attica prefecture, and from 1994, part of the Athens-Piraeus super-prefecture (1994–2011). The capital of the prefecture was Piraeus. As a part of the 2011 Kallikratis Programme, the prefecture was abolished, and its territory was divided into two regional units: Islands and Piraeus.{{cite web |title=Law 3852/2010 (Kallikratis reform) |url=https://www.kodiko.gr/nomothesia/document/132966/nomos-3852-2010 |url-status=live |archive-url=https://web.archive.org/web/20240401181332/https://www.kodiko.gr/nomothesia/document/132966/nomos-3852-2010 |archive-date=2024-04-01 |access-date=2024-04-01 |language=el}}