The Yerevan trolleybus system (Armenian: Երևանի տրոլեյբուսային համակարգեր) forms part of the public transport network in Yerevan, the capital city of Armenia. Since the closure of the Gyumri trolleybus system in 2005, it has been Armenia’s only trolleybus system.

Opened on 16 August 1949, the system was once much more extensive than it is today. At its greatest extent, the system had 20 lines, operated by a total of 300 trolleybuses, the vast majority of which were either Czech made Škoda 9Tr or 14Tr units, or Soviet made ZiU-682 models.^[1]

In recent years, the system has shrunk, and most of the Soviet era trolleybuses have been replaced by newer vehicles.^[2]

As of 2011, the system was made up of the following lines: 1, 2, 9, 10 and 15. In July 2023, 2 new lines were introduced as new buses arrived to the fleet. Lines 2a and 10a are extended versions of lines 2 and 10, the lines continue without wires which was made possible with the new buses.

The Yerevan trolleybus fleet still has a significant number of Škoda 14Tr units in service. The Škoda 9Trs and ZiU-682s have all been withdrawn.^[1]

The latest trolleybuses in the fleet are mostly Russian made LiAZ-5280 vehicles, and second hand Berliet ER100 trolleybuses originally used on the Lyon trolleybus system.^[1]

In 2019, it was announced that daily ridership of the system was 14,500. Former deputy Mayor of Yerevan, Hrachya Sargsyan, stated that 101 new trolleybuses for new routes is planned. In 2023, 15 new Yutong trolleybuses joined the system and there are plans to buy an additional 15 new units.^[3]

On 16 September 1976, a trolleybus operating alongside Yerevan Lake went out of control and fell from the dam wall into the lake. The sound of this accident was heard by Shavarsh Karapetyan, a multi-champion finswimmer, who was training with his brother Kamo, also a finswimmer, by running alongside the lake.^[4] The trolleybus lay at the bottom of the reservoir some 25 meters (80 ft) off the shore at a depth of 10 meters (33 ft). Karapetyan swam to it and, under conditions of almost zero visibility due to the silt rising from the bottom, broke the back window with his legs. The trolleybus was crowded, it carried 92 passengers and Karapetyan knew he had little time, spending some 30 to 35 seconds for each person he saved.^[4] Karapetyan managed to rescue 20 people, but this was the end of his sports career: the combined effect of cold water and the multiple wounds he received left him lying unconscious for 45 days, with subsequent sepsis (due to the presence of raw sewage in the lake water) and lung complications preventing him from continuing his sports career.^[4]

• List of trolleybus systems
• Transport in Armenia
• Trolleybuses in former Soviet Union countries
• Trolleybus usage by country
• Yerevan Metro