WASHINGTON—President Barack Obama said he is nominating the first U.S. ambassador to Cuba in more than 50 years, a move certain to anger those lawmakers on Capitol Hill who oppose the administration’s move to normalize relations with Havana.

The nominee, Jeffrey DeLaurentis, has been the most senior U.S. official in Havana since the summer of 2014. He is currently the chargé d’affaires at the embassy and lives in the ambassador’s residence in Havana.

“The...