Born in Lahore in 1952, Jahingir braved death threats, beatings and, at one time, claimed Pakistan's much-feared Inter-Services Intelligence (ISI) spy agency was trying to murder her.
"Her demise is a big loss for the marginalised communities in Pakistan, a loss for the secular people of Pakistan, and a loss for the voice of reason". She was appointed UN Special Rapporteur on Extrajudicial, Arbitrary or Summary Executions and later as the UN Rapporteur of Freedom of Religion or Belief.
Pakistani Nobel Peace Prize victor Malala Yousafzai said on Twitter she was "heartbroken" at the death of the "savior of democracy and human rights", especially as the pair had just met in Britain a week ago.
"Just heard the devastating news that Asma Jehangir passed away".
Punjab Chief Minister Shahbaz Sharif tweeted: "Pakistan has lost a passionate champion of human rights and a staunch supporter of democracy..."
"She has fought against the military dictators and also for the rights of downtrodden individuals".
She said Pakistan should first take up the issue of capital punishment through unfair trials here and of those Pakistanis who were being consistently executed in Saudi Arabia and then show disproportionately high passion for the politicians of Bangladesh.
She notably critiqued the misogynistic and barbaric, enacted in 1997 under Zia Ul Haq, among other Pakistani laws that were misogynistic, archaic, and discriminatory towards religious minorities.
In 2007, she was put under house arrest by the military regime of Pervez Musharraf, another general, for her active role in Lawyers Movement for the restoration of deposed judges.
Her daughter Munizae Jahangir confirmed the news of her death.
Zohra Yousuf, a former chairwoman of the Human Rights Commission of Pakistan, said she lost a "great friend and great warrior of human rights".
Jahangir received several national awards, including the Sitara-I-Imtiaz in 1995.
A fierce defender of democracy, Jahangir was an outspoken critic of Pakistan's powerful military establishment and Islamic extremists. She was awarded the Nobel Peace Prize in 2014 and is now studying at Oxford. Jahangir also won numerous awards over the years including a UNESCO/Bilbao Prize for the Promotion of a Culture of Human Rights and an Officier de la Légion d'honneur by France. She was courageous, fearless, invincible.