President-elect Donald J. Trump picked Scott Bessent to serve as Treasury secretary on Friday, tapping a billionaire hedge fund manager to lead an economic agenda that is expected to be built around raising tariffs and cutting taxes.

Mr. Bessent, the founder of the investment firm Key Square Capital Management, has emerged as a central economic adviser to Mr. Trump over the past year. He has called for rolling back government subsidies, deregulating the economy and raising domestic energy production. Unlike many on Wall Street, Mr. Bessent, 62, has also defended the use of tariffs, which are Mr. Trump’s favorite economic tool.

“Scott is widely respected as one of the World’s foremost International Investors and Geopolitical and Economic Strategists,” Mr. Trump said in a statement posted on social media. “Scott’s story is that of the American Dream.”

“Together, we will Make America Rich Again, Prosperous Again, Affordable Again, and most importantly, Great Again,” Mr. Trump said.

Although Mr. Bessent’s policy ideas are in lock step with conservative economic principles, one aspect of his background could draw questions from Republicans. He rose to prominence in the finance world as a protégé of George Soros, the billionaire Democratic donor and longtime villain of the right wing, and served for years as his top money manager.

The selection came after intensive deliberation by Mr. Trump and his advisers, who debated for weeks about who should win the most prominent economic job in his administration. Mr. Bessent and Howard Lutnick, the chief executive of Cantor Fitzgerald, tussled over the job before Mr. Lutnick was picked to be commerce secretary this week. Mr. Trump also considered tapping Kevin Warsh, a former Federal Reserve Board governor, and Marc Rowan, the chief executive of Apollo Global Management, for the role.