Line 3 (Athens Metro)

Line 3 of the Athens Metro is a rapid transit line that runs from Dimotiko Theatro in the west to Doukissis Plakentias or Athens Airport in the east, via Syntagma. Most Line 3 trains start or terminate at Doukissis Plakentias: a through service to the Airport leaves once every 36 minutes, and shares most of the extended route with the Athens Suburban Railway.

Line 3 provides a direct albeit infrequent service between the Port of Piraeus with the Athens International Airport, a journey that takes up to 59 minutes. The line between Dimotiko Theatro and Doukissis Plakentias is underground, and the shared section with the Athens Suburban Railway towards the Airport is a surface-level median of the A6 and A62 motorways.

It first opened, between and, on 28 January 2000, with Line 2. In 2012, construction works commenced for the latest underground extension of Line 3 to via  which was completed on 10 October 2022.

Rolling stock
Dual voltage ROTEM-supplied stock with greater luggage space is used for services to Athens International Airport. Line 3 rail vehicles utilize 750 V DC third rail current collection between Dimotiko Theatro and Doukissis Plakentias, changing to 25 kV AC overhead catenary while operating on the Athens Suburban Railway for access to/from the airport.

Extension to Piraeus
On 1 March 2012 a contract was signed between Attiko Metro S.A. and a joint venture for the construction of the extension of Line 3 from Haidari to Piraeus, 7.6 km long with six stations. The extension to Nikaia in 2020 brought the Korydallos and Nikaia municipalities into the network's catchment area, serve approximately 132,000 passengers on a daily basis and upon completion in 2022, connects to the port of Piraeus, the largest passenger port of Europe with the Athens International Airport in just 1 hour. The completion dates of the final three stations are as follows:
 * Maniatika (10 October 2022)
 * Piraeus (10 October 2022)
 * Dimotiko Theatro ("Municipal Theatre", 10 October 2022)


 * Notes
 * The original plans included one more station after Dimotiko Theatro, named Evaggelistria. Attiko Metro cancelled plans for the station on 10 November 2008, due to local objections (mainly by the Metropolitan Bishop of Piraeus District).
 * There were plans to build a station between Korydallos and Nikaia named Perivolaki.

2018 timetable controversy
On 1 November 2018, STASY introduced a new timetable that scrapped direct metro services to the airport from the city center, due to the lack of spare parts for the fleet. At the time, travelers from the city center to the Airport had to change at Doukissis Plakentias. Reception towards the timetable changes was overwhelmingly negative: the negative reception included a complaint by the Minister for Transport, Thanos Vourdas, claiming that STASY required ministerial approval to scrap the airport trains. On 9 November 2018, STASY decided to reinstate the original service pattern, from 10 November 2018.

Stations
The spelling of the station names on this table, in English and Greek, are according to the signage. Most Line 3 stations have two tracks and two side platforms: Egaleo, Ethniki Amyna, Koropi, Monastiraki, Paiania–Kantza and Pallini have two tracks and one island platform. Athens Airport has three tracks and two island platforms, but Metro trains can only use the middle track.