Istanbul, the former capital of the Ottoman Empire, once had a large tramway network on both the Asian and the European sides. It first started as a horse tram in 1860, and was gradually converted to an electric tram system starting in 1912. Many additional routes were added to the tram system, in progressive stages over time. The network reached its most widespread extent in 1956 with 108 million passengers being carried by 270 tram-cars, on 56 lines. However reflecting developments in many cities around the world during the 1960s, the tram service began to be closed down in 1956, and was completely stopped in 1966.

After closing the old tram network in the mid-1960s, the people of Istanbul thought the unfashionable obstacle to smooth city travelling had been removed, and that city traffic would move faster than before, but it proved false some years later. An uncontrolled increase in the use of fossil fuel vehicles like buses, taxi, and private cars started choking the streets of Istanbul. Turkey suffered many of the problems of developing countries, including pollution, traffic jam, illegal migration, low literacy and high levels of population increase etc. As the Population density grew, Istanbul became increasingly urbanized, leading to growing numbers of motor vehicles. This in turn led to increased air and sound pollution, traffic congestion and smog. The city became slower than had been the case prior to the closure of the former tramway system. These problems became apparent in the early '70s; during the mid '80s Istanbulites realized that uncontrolled motor vehicles access and the termination of the tram system had been a mistake. The increase in traffic, congestion and resulting air pollution led to Istanbul becoming one of the most polluted Eurasian cities during the mid '80s. After realising this error, Istanbul planned for the return of trams.[citation needed]

Understanding the great mistake of former tram closure, the government started to decrease pollution as soon as possible, and also recover the good image of Istanbul for tourists. Istanbul's transport authority decided to open a separate, modern, high speed tram.

The modern tramway, called the T1 line, was introduced in Istanbul in 1992, and soon became popular. The T1 tramways has gradually been extended since that time, the last extension being in 2011.

A second modern tramway between Edirnekapı and Mescid-i Selam, called the T4 line, was opened in 2007. The line was extended to Topkapı in 2009.

Timeline  Tramway lines in the railway-network in Istanbul: T1 (blue) and T4 (orange)1961 – The last tram ran on the European side on 12 January. Topkapı-Eminönü line was replaced by trolleybuses on 27 May. Six trams were transferred to the Asian side network. 1966 – The last tram ran on the Asian side on 3 October from Kadıköy to Üsküdar.[1] Remaining trams were transferred to the transport museum. 1984 – Trolleybus service ended on 16 July. Thus all electric city transport in Istanbul was eliminated, apart from the Tünel (funicular). 1990 – İstiklal Caddesi (Independence Avenue) was closed to traffic. Trams returned to the European side of Istanbul as a heritage tram line, the Taksim-Tünel Nostalgia Tramway (sometimes called T5 line), operating on İstiklal Caddesi between Taksim and Tünel. Rolling stocks were same as the pre-1966 trams. 1992 – By opening a completely separate tram system, trams returned to Istanbul as a modern system. It started on the same alignment where trams last ran in 1956. The first service was started between Beyazıt & Yusufpaşa as line T1. It was served by high-floor light rail vehicles. 2003 – Trams returned to the Asian side of Istanbul as heritage tramway, operating a circular tramway on the old closed Route 20 tramway. The rolling stock was imported from Gotha, Thuringia, Germany. This line is now known as the T3 tramline (or the Kadıköy-Moda Nostalgia Tramway). 2004 – T1 line's rolling stock was replaced by low-floor Bombardier Flexity Swift trams.[2] 2006 – Tram system extends farther west, but as a separate line: T2. Although both lines' gauges were the same, T2 used high-floor light rail vehicles (LRVs) rolling stock. 2007 – Another tramline, named T4, which uses high-floor light rail vehicles (LRVs), opened. 2009 – Plans to replace all high-floor ABB, Duewag and Rotem trams with Alstom Citadis low floor trams, while connecting T1 and T2, were implemented. T4 line extended to Topkapı. 2011 – The first Alstom Citadis low-floor trams enter service.[3] As a result, the combination of lines T1 and T2, into a new single line T1, is complete. 2016 – Tenders for the new Eminönü-Alibeyköy line to be constructed along the Golden Horn were received on 29 June.[4] 2021 – The first segment of Istanbul's T5 tram line alongside the Golden Horn waterway opened on 4 January.[5] 2023 - Remaining portion of T5 between Cibali and Eminönü opens on 30 August. 2024 - The T6 tram line reusing the old Kazlıçeşme-Sirkeci commuter rail alignment begins operation on 26 February.