World Bank President Jim Yong Kim is the latest in a series of high-profile departures for Saudi crown prince Mohammad Bin Salman's upcoming economic development conference.
The World Bank confirmed the move to Anadolu Agency.
Bin Salman's Future Investment Initiative Conference, slated to run Oct. 23 - 25, is part of his Vision 2030 plan to ween the kingdom off its reliance on oil.
Kim is joining a growing list of former attendees including billionaires, media companies, journalists and tech firms pulling out of what has been termed "Davos in the desert" over the disappearance of Washington Post journalist Jamal Khashoggi, who has been missing since Oct. 2 when he was last seen entering the Saudi Consulate in Istanbul.
Among the big names who have dropped their support are Uber CEO Dara Khosrowshahi, billionaire philanthropist and Los Angeles Times owner Patrick Soon-Shiong, editor-in-chief of the Economist Zanny Minton Beddoes, and British billionaire Richard Branson.
The New York Times, CNN, CNBC and have also announced they would not sponsor the event, and several prominent journalists have said they would not attend.
Karen Attiah, who edits the Global Opinions section of the Washington Post, the outlet Khashoggi worked for, urged a boycott of bin Salman's flagship conference.
"American investors, media professionals and government officials are going to Saudi Arabia for its Future Investment Initiative conference in Riyadh Oct 23," she wrote on Twitter. "After WaPo journalist Jamal #Khashoggi’s likely murder by KSA, these partners should WITHDRAW."
She was referring to the Kingdom of Saudi Arabia, sometimes referred to as KSA.
Speculation continues to grow that Khashoggi was killed by Saudi authorities after entering the consulate.
On the same day that he arrived at the diplomatic building, 15 Saudis, including several officials, arrived in Istanbul on two planes and visited the consulate while Khashoggi was also inside, police sources said. All of the identified individuals have since left Turkey.
Saudi authorities have yet to give a clear explanation of Khashoggi’s fate, while several countries -- particularly Turkey, the U.S. and the UK -- have expressed their desire that the matter should be elucidated as soon as possible.
*Gulbin Yildirim contributed to this story
By Michael Hernandez in Washington