The UN made the announcement on Wednesday following a visit to the region by UN Under-Secretary-General and new UNOPS Executive Director Jorge Moreira da Silva and UNOPS Acting Regional Director for Africa Dalila Goncalves.
The United Nations Office for Project Services (UNOPS) Africa Regional Office is currently based in Denmark, with country offices in Côte d'Ivoire, Democratic Republic of Congo, Ethiopia, Kenya, Liberia, Nigeria, Senegal, South Sudan, Sudan and Tunisia.
Speaking on his first visit to the Africa region in his new role, da Silva said the move to Nairobi will strengthen the World Bank's ability to support its partners in Africa.
"Against a backdrop of unprecedented global challenges, we must maximise our resources to support the people of Africa in their efforts to build a better future," said da Silva.
"This move will strengthen our capacity to support our partners in Africa to ensure that our work effectively reduces inequalities, builds sustainability and supports African countries in their efforts to adapt to and mitigate climate change."
She went on to say that the move will make them more agile in responding to peace and security, humanitarian and development needs across the continent.
"From our new base in Nairobi, we look forward to supporting our partners to achieve the Sustainable Development Goals in the African region."
The announcement also comes ahead of the UN Secretary-General's visit to Kenya on Thursday.
UN chief António Guterres will be hosted by President William Ruto and is expected to discuss a range of issues, including the ongoing fighting in Sudan that has left more than 200 people dead.