Zoellick will leave at the end of his five-year term and the administration of U.S. President Barack Obama was expected to name a successor soon.
Zoellick's leadership of the bank, based in Washington, was particularly notable during the global economic crisis, during which the institution came up with record replenishments to provide more than $247 billion to help developing countries boost growth and overcome poverty.
"I'm honored to have led such a world class institution with so many talented and exceptional people. Together we have focused on supporting developing countries to navigate crises and adjust to global economic shifts," Zoellick said in his announcement, the Bank's Web site reported.
Zoellick said the traditional concepts of the "Third World" are outdated, with developing countries having a key role as growth drivers and responsible stakeholders.
"I'm very pleased that when the world needed the Bank to step up, our shareholders responded with expanded resources and support for key reforms that made us quicker, more effective and more open," Zoellick added. "The Bank is now strong, healthy and well positioned for new challenges, and so it is a natural time for me to move on and support new leadership."
Zoellick, 58, told The New York Times in an interview he had no immediate future plans. However, the report said the longtime member of the Republican foreign and economic policy team has been mentioned as a likely Treasury Secretary if a Republican becomes the next U.S. president.
The Times said current Treasury Secretary Timothy Geithner, along with White House National Security Adviser Thomas Donilon and Jacob J. Lew, the chief of staff, were consulting with President Barack Obama on a choice to succeed Zoellick and the team expects to make an announcement in the next few weeks.
The Times said Secretary of State Hillary Clinton has been mentioned often for the World Bank presidency, although the State Department has denied that. Former Treasury Secretary Lawrence Summers is also mentioned as a possible nominee.
Traditionally, the United States has appointed the Bank's leader, while Europe chooses the leader of the International Monetary Fund.