IMF chief economist Gita Gopinath will leave her post and return to Harvard University's economics department in January, the fund announced Tuesday.
Harvard extended Gopinath's leave of absence by one year, which allowed her to serve at the IMF for three years, the statement said.
She heads the International Monetary Fund's research department which produces the quarterly World Economic Outlook report with its closely watched GDP growth forecasts.
IMF Managing Director Kristalina Georgieva praised Gopinath, who "made history" as the first woman to serve in the top economics post, for her critical analysis during the pandemic.
"Gita's contribution to the Fund and our membership has been truly remarkable -- quite simply, her impact on the IMF's work has been tremendous," Georgieva said in a statement.
"We benefitted immensely from her sharp intellect and deep knowledge of international finance and macroeconomics as we navigate through the worst economic crisis since the Great Depression."
She had a key role in setting global vaccination targets to end the Covid-19 pandemic, and also helped set up a Climate Change team inside the IMF to analyze, among other things, optimal climate mitigation policies, Georgieva said.
Gopintath's decision to leave was not linked to the recent controversy surrounding Georgieva, according to a person familiar with the matter.
Georgieva, who previously served in a top position at the World Bank, was implicated in an investigation showing officials pressured economists to alter results of the bank's closely-watched "Doing Business" report that ranked countries based on business-friendly policies.
But the IMF board last week expressed confidence in Georgieva and said the report did not conclusively show she "played an improper role."
Gopinath's decision to leave the fund was "unrelated to the events the last few weeks," the person told AFP.
Gopinath, a dual US-Indian citizen, was appointed to her role in October 2018.
The IMF said the search for a replacement will begin shortly.