Johnson is a former high-ranking Pentagon official who was key in the repeal of "don't ask, don't tell."
Below, more from the AP:
WASHINGTON (AP) — President Barack Obama has chosen former Pentagon lawyer Jeh (jay) Johnson as the new secretary of the Homeland Security Department.
Obama plans to announce Johnson's nomination Friday. He must be confirmed by the Senate before taking over the post most recently held by Janet Napolitano (neh-pahl-ih-TAN'-oh). Napolitano stepped down in August to become president of the University of California system.
A senior administration official on Thursday confirmed Johnson's selection, first reported by The Daily Beast. The official said Obama chose Johnson because of his experience as a national security leader.
The official was not authorized to speak about the nomination on the record and spoke on condition of anonymity.
This story has been updated with more from the AP.