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.

“Sally is an incredible leader and a supremely talented media executive who will be sorely missed,” Mr. Lewis said in a statement. “I wish her all the best going forward.”

Ms. Buzbee and Mr. Murray didn’t immediately respond to requests for comment.

The new appointments are the biggest moves that Mr. Lewis has made since he was appointed C.E.O. last year. He has focused on remaking the top ranks of the company. In April, The Post hired Suzi Watford, a former top executive at Dow Jones, the publisher of The Journal, as its chief strategy editor. In January, The Post named Karl Wells as its chief growth officer, a position responsible for subscription strategy, partnerships, licensing and data analytics.

At a town hall last month, Mr. Lewis updated employees on his strategy for reviving the business and revealed the extent of The Post’s financial woes, including that it lost more than $70 million in 2023 and suffered a substantial decline in audience.

On Sunday, Mr. Lewis unveiled more of his plan to save The Post, including the new division of the newsroom focused on service, which will target nontraditional news consumers. The core news division will soon include premium subscription products, similar to Politico Pro.

Mr. Murray, 58, led The Journal for four years, a job he was appointed to by Mr. Lewis, who was then the chief executive of Dow Jones and the publisher of The Journal. Mr. Murray was replaced in 2023 by the British editor Emma Tucker. He has since served as a consultant to News Corp, which owns The Journal, and has worked as a contributing editor to News Items, an email newsletter.

When Mr. Winnett takes over the core newsroom after the election, he will oversee coverage areas such as politics, investigations and business. For the past decade, Mr. Winnett has run news operations at The Daily Telegraph and The Sunday Telegraph.

A habitué of Fleet Street, Mr. Winnett is relatively unknown in the top echelons of the U.S. news industry. He was one of Mr. Lewis’s most prominent hires at The Daily Telegraph, having been nominated multiple times for Scoop of the Year.

Ms. Buzbee joined The Post in June 2021 after serving as executive editor of The Associated Press, where she spent her whole career. She took over The Post from Marty Baron, a legendary newspaper editor who had run The Post for eight years and oversaw its transition to ownership by Jeff Bezos, the Amazon founder, who bought the paper for $250 million in 2013.

Fred Ryan, the former chief executive of the company, stepped down last June, and was replaced in the interim by Patty Stonesifer, an Amazon board member. Ms. Stonesifer, a confidant of Mr. Bezos, assessed the company and soon determined that it needed to cut about 240 jobs in order to become economically sustainable. Ms. Stonesifer led the search for her successor, and recruited Mr. Lewis to The Post last year.