The executive editor of The Washington Post, Sally Buzbee, will leave her role, a major and sudden change at one of the nation’s pre-eminent news organizations.

Matt Murray, the former editor in chief of The Wall Street Journal, will take her place through the presidential election, the company said on Sunday night. He will start in the role immediately. Robert Winnett, a deputy editor of the Telegraph Media Group in Britain, will take over after the election.

Mr. Murray will then transition to a new role, the company said in a news release, building a new division of The Washington Post focused on service and social media journalism.

At that point, Mr. Winnett, Mr. Murray and David Shipley, who oversees the opinion section at The Post, will each report independently to Will Lewis, the chief executive and publisher.

Ms. Buzbee, 58, steered the newspaper for the last three years, a turbulent period that resulted in award-winning journalism as well as a drop in audience and an exodus of some top talent.

The Post has greatly expanded its editing ranks under Ms. Buzbee, announcing the addition of roughly 41 positions in 2021, and revamping its vaunted Style section. It has received six Pulitzer Prize awards since she joined, three of them this year. The paper also shut down its Sunday magazine, a move that upset many of the newspaper’s feature writers.