The Murdoch family, in the throes of reshaping its media empire, is bringing on a lieutenant with experience in chaotic environments: President Trump’s former communications director, Hope Hicks.

Starting next year, Ms. Hicks, one of the most recognizable alumni of Mr. Trump’s White House, will become the chief communications officer of Fox, the new entity to be spun out of the Walt Disney Company’s acquisition of most of 21st Century Fox.

She plans to move to Los Angeles in connection with her new job. A native of Greenwich, Conn., she had been living in Manhattan since leaving the White House this year.

Ms. Hicks, 29, was an obscure public relations aide with zero political experience when Mr. Trump plucked her from his family business in 2015 to serve as press secretary for his nascent presidential bid. What followed was a remarkable ascent, as Ms. Hicks weathered staff shake-ups and a knives-out office environment to become the closest aide to the most powerful man in the world.