Yeşilköy (Turkish pronunciation: [jeˈʃilcøj]; is a neighbourhood in the district of Bakırköy Istanbul, Turkey. It is located along the Marmara Sea about 11 kilometres (7 miles) west of Istanbul's historic city centre. Before the rapid increase of Istanbul's population in the 1970s, Yeşilköy was merely a village and a sea resort.
Prior to 1926 known as San Stefano or Santo Stefano from the Greek: Άγιος Στέφανος pronounced Aghios Stefanos, rendered in Turkish as Ayastefanos, its former names (meaning Saint Stephen) derive from a legend: in Byzantine times, the ship carrying the bones of the saint from Constantinople to Rome was forced to stop here because of a storm. The bones were taken to a church until the sea calmed down, and this gave the name to the church and to the place.
During the Crimean War, the French forces were stationed here, and built one of the three historic lighthouses of Istanbul still in use. Yeşilköy is also where the Russian forces stopped at the end of the war of 1877-1878 and was the location where the Treaty of San Stefano was signed between Russian and Ottoman Empire. In 1909, the decision to send Sultan Abdülhamid II in exile to Thessaloniki was taken by the members of the Committee of Union and Progress at the Yacht club of Yeşilköy.
On 10 July 1894 Istanbul experienced a strong earthquake, whose aftershocks lasted three days. The quake hit Yeşilköy too. The sea receded 100 meters from the shore and the following tsunami created giant waves which devastated the coast. The boathouse, the docks and large wooden structures were damaged, many houses were destroyed or damaged and also the train track was severely damaged by the quake.
In the nineteenth and early twentieth centuries, Yeşilköy was a favourite coastal resort and hunting place for Istanbul's upper class, and had a mixed population, made of Turks, Greeks, (now almost completely emigrated), Armenians (who still live there in numbers) and Levantines (Italian and French people of Istanbul - now almost completely emigrated). As a legacy of the district's cosmopolitan character, an Italian mission, an Italian Catholic church and cemetery, Armenian churches and Greek churches still exist in the area. All the churches are dedicated to St. Stephen.
The village got its present name (Turkish: Yeşilköy : "Green Village") in 1926, because of the legislation which imposed to give a Turkish name to each community. The name was given by the writer Halit Ziya Uşakligil, who lived here.
Yeşilköy today 
Yeşilköy – whose population is mainly affluent - retains some notable examples of wooden Art Nouveau houses built between the end of the nineteenth and the beginning of the twentieth centuries. It has a Marina - the Yeşilköy Burnu Marina -  and sandy beaches.
Istanbul Atatürk International Airport, formerly known as the Yeşilköy Airport, is located in this district. The headquarters of Turkish Airlines are on the property of the airport. MyCargo Airlines (formerly ACT Airlines) has its head office in Level 4, Building A3 of the Istanbul World Trade Center (Istanbul Dunya Ticaret Merkezi) in Yeşilköy. Borajet also has its head office in Yeşilköy. When Bestair existed, its head office was in Yeşilköy.
The first military aviation base was established in Yeşilköy in 1909-1911.
Images of Yeşilköy 
View of the Marmara Sea from Yeşilköy
- Yeşilköy, istanbul.com, retrieved 24 February 2012
- Yesilkoy Burnu, 1.yachtua.com, retrieved 24 February 2012
- "Contact Us." Turkish Airlines. Retrieved on 24 June 2009.
- "ACT Airlines Headquarters." ACT Airlines. Retrieved on 23 November 2012. "Istanbul World Trade Center (Istanbul Dunya Ticaret Merkezi) Building A3, Level 4, 34149 Yesilkoy - Istanbul / TURKEY"
- "Contact Us." Borajet. Retrieved on 16 February 2011. "ADDRESS İDTM Blokları A-3 Blok Kat:5 Yeşilköy 34149 / İstanbul-TURKEY"
- Home page. Bestair. 25 March 2008. Retrieved on 30 January 2012. "İSTANBUL D.T.M. A3 Blok Kat:5 Yeşilköy İstanbul"
- Tuna, Turgay (2004). Ayastefanos'tan Yeşilköy'e (in Turkish).
Media related to Yeşilköy at Wikimedia Commons