Medina-Mora had been chairman and chief executive officer of Latin America and Mexico.
Chief Executive Officer Vikram Pandit called Medina-Mora an "exceptional banker" in a statement issued Monday.
"We are now focused on developing our client franchise in our core business. Under Manuel's leadership, we will build on the progress we have made," Pandit said.
The bank's North America Consumer Banking includes more than 1,000 branches and 12 million retail banking accounts and 25 million branded credit cards.
Its Global Consumer division includes 4,200 branches in 38 countries serving more than 46 million clients, Citigroup said.
Medina-Mora has a masters of business administration from Stanford University. He has served as chairman and chief executive officer of Citi Latin America since 2004.