The 42-year-old former journalist has emerged as the leader of a movement confronting established politics in Armenia. Denied the prime ministership, Pashinyan says he will push ahead with a radical overhaul of politics as usual.
Here is a look at Nikol Pashinyan, the Armenian opposition figure leading mass protests against the ruling establishment:
Pashinyan was born in Ijevan, northeastern Armenia, in 1975.
He worked as a journalist and produced work which was critical of Robert Kocharyan and Serzh Sargsyan, the two men who have dominated political life in Armenia since the late 1990s. He rose to be editor of Armenian newspaper Haykakan Zhamanak.
During the 2008 presidential campaign, Pashinyan aligned himself with Levon Ter Petrosyan, Armenia's first president since it became an independent state in 1991, who was making an unsuccessful comeback bid.
Pashinyan was imprisoned in June 2009 on charges of fomenting unrest during post-election protests that turned violent. Pashinyan was sentenced to four years in prison. He was released two years later under amnesty.
In a 2017 parliamentary election, Pashinyan was elected a member of the national assembly.
Pashinyan emerged as the leader of a protest movement after Sargsyan, forced to step down as president because of constitutional term limits, announced he would seek to become prime minister instead. After days of mass protests, Sargsyan announced he was quitting the prime minister's post.
Pashinyan has not questioned Armenia's geopolitical alignment with Russia under Sargsyan and his criticism has focused on domestic issues such as corruption and poverty.
In public appearances, he often wears a camouflage T-shirt and cap, though he swapped that outfit for a jacket and tie on Tuesday when he asked parliament to choose him as the next prime minister.