United Nations Secretary General Antonio Guterres has appointed Ms Winnie Byanyima as the new HIV/AIDS chief.
Oxfam International executive director Winnie Byanyima of Uganda will lead UNAIDS, a spokesperson for Guterres said in a statement.
Ms Byanyima has held several roles that affiliated to the governance of the African Union, and has influenced the international agenda at the United Nations through her leadership in many coalitions of civil society organizations.
She, at the time of her appointment, was the Executive Director of OXFAM, a position she has held for six years since her appointment in January 2013.
Ms Byanyima is taking over from Micheal Sidibe who stepped down in May this year following accusations of ''serious mismanagement''. Mr Sedibe was also accused of creating "a patriarchal culture tolerating harassment and abuse of authority."
An Independent Expert Panel (IEP) report commissioned by UNAIDS's governing body said the agency's culture under Sidibe also failed "to uphold the United Nations' laws and values.
Sidibe left UNAIDS after a decade-long tenure to become Mali's health minister.
Guterres continued to praise Sidibe despite his being reprimanded for mishandling a sexual assault investigation involving one of his top deputies.
Sidibe's divisive era led AIDS experts to voice concern over the future of the UN body, which UNAIDS leads a global effort to end AIDS as a public health threat by 2030.
In the statement announcing Byanyima's appointment, Guterres said she "brings a wealth of experience and commitment in harnessing the power of government, multilateral agencies, the private sector and civil society to end the HIV and AIDS crisis for communities around the world."
Byanyima, 60, said she was "honored" to be joining UNAIDS "at such a critical time in the response to HIV."
"An honour to be asked to lead the UN and global HIV response! I embrace the role with humility, passion and faith that we can end this pandemic by 2030. I look forward to joining
UNAIDS," Ms Byanyima said in a tweet.
AIDS-related illnesses have killed 35 million people since the first cases were reported more than 35 years ago.
In Uganda alone, the number of new infection stand at 83,265, according to the Uganda HIV/AIDS Country Progress Report (July 2015 – June 2016) that was released at the Annual Joint AIDS Review and Partnership Forum.