The two-term Chilean ex-leader and torture survivor will face a host of challenges in her new role. Bachelet's moves will also be closely watched by Israel and the US, who repeatedly criticized her predecessor.
UN Secretary-General Antonio Guterres announced on Wednesday that he has chosen Chile's former President Michelle Bachelet to be the next human rights chief.
On Friday, the UN General Assembly will vote on her nomination, which is expected to be approved.
Bachelet was Chile's first female president, serving for two terms from 2006-2010 and 2014-2018. She was also the first head of UN Women, an agency dealing with gender equality that was formed in 2010.
She will succeed Zeid Ra'ad Al-Hussein as the head of the Office of the High Commissioner for Human Rights.
Zeid, who served in the role since 2014, is due to step down from the post on August 31. Criticized by several countries for being too outspoken, Zeid decided not to seek a second term in the post after losing the support of the United States, Russia and China.
Bachelet is known for being a champion for women's rights in both her work as a politician and earlier career as a pediatrician. She's also familiar with human rights abuses, having experienced them under the Pinochet regime in Chile.
Bachelet's father was a general who opposed August Pinochet's overthrow of President Salvador Allende. Her father was imprisoned for treason and eventually died after months of torture.
Bachelet and her mother were also detained and tortured for weeks before they fled into exile in Australia and later East Germany.
"I was lucky compared to so many others. Many of them died," Bachelet said in the 2014 interview about her ordeal.
Bachelet's administration was rocked by corruption scandals during her second term and she was criticized for corporate tax hikes that were seen as discouraging foreign investment in Chile.
'One of the world's most difficult jobs'
If confirmed, Bachelet will face scrutiny from several countries whose leaders were called out for human rights abuses by her predecessor Zeid.
Zeid defended his criticism of abuses committed in dozens of countries, saying during a farewell conference last week that the UN office does not "bring shame on governments, they shame themselves."
Bachelet will face scrutiny especially from Israel and the United States, which said Zeid's office unfairly targeted the Israeli government.
Nikki Haley, the US ambassador to the UN, advised Bachelet to "avoid the failures of the past." Washington announced its withdrawal from the Human Rights Council in June over its criticism of Israel.
Kenneth Roth, the executive director of Human Rights Watch, said Bachelet "will be taking on one of the world's most difficult jobs," saying that human rights are currently under threat around the world.
"As a victim herself, she brings a unique perspective to the role of the importance of a vigorous defense of human rights. People worldwide will depend on her to be a public and forceful champion, especially where offenders are powerful," Roth said in a statement.
rs/sms (AP, AFP, dpa)