The announcement came during an on-air interview with Fox — Ms McEnany’s first since the end of the Trump administration — when host Harris Faulkner welcomed her to the network.
“It is my distinct pleasure to welcome Kayleigh McEnany to the Fox family,” Ms Faulkner said. “We will be seeing much more of her.”
The news comes after weeks of speculation about the possibility of Ms McEnany joining the network, and what role she might take.
Ms McEnany’s financial disclosure form when she left the White House said she had reached an agreement with the company in January 2021.
She appeared on the network more than 20 times after Mr Trump lost the 2020 election.
A former CNN contributor, Ms McEnany was a spokesperson for the Trump re-election campaign until last spring when she was elevated to White House press secretary following the exit of Stephanie Grisham.
Ms Grisham was notable for not holding a single formal press briefing in her 281 days on the job. She succeeded Sarah Huckabee Sanders who held the role for just under two years and is now running to be governor of Arkansas.
Mr Trump’s first press secretary was Sean Spicer, who now hosts a talk show on Newsmax.