The Washington Post has named longtime journalist Sally Buzbee of the Associated Press as its executive editor, marking the first time a woman has been appointed to lead the 143-year-old news organization.

Buzbee, AP’s executive editor and senior vice president, will take over leadership of The Post’s nearly 1,000-person newsroom next month, said publisher Fred Ryan, who made the announcement to the newspaper’s staff on Tuesday.

She succeeds Martin Baron, who retired at the end of February after serving as editor since 2013. Her appointment ended a search that began 10 weeks ago, following Baron’s retirement.

Buzbee, 55, has headed AP’s news operations since 2017, and has been with the organization since she began her career as a journalist in 1988. The venerable wire service, headquartered in New York, is one of the largest news organizations in the world, with about 2,800 journalists. Like The Post, it produces hundreds of news articles, feature stories and photos every day that are distributed to news outlets worldwide. It also produces audio and video reports that are carried on TV and radio stations.

Buzbee’s experience overseeing international newsgathering made her an attractive candidate as The Post expands its operations abroad, Ryan said. The newspaper has announced plans to open news hubs in London and Seoul this year that will enable its newsroom to report stories around-the-clock. It will also open bureaus in Sydney and Bogotá, Colombia, expanding its total to 26 outside the United States.

Buzbee also has Washington ties. From 2010 to 2016, she was AP’s Washington bureau chief, and was in charge of its coverage of the 2012 and 2016 presidential elections, as well as its coverage of Congress, the White House and federal agencies. During an earlier stint in Washington in the 1990s, she was AP’s assistant bureau chief for news, running spot news coverage and overseeing the foreign affairs and national security beats.

“The Post has such a rich journalistic legacy, and such a terrific staff,” she said in an interview Tuesday morning from her home in New York City. “It’s exciting to join this organization at a time of growth and innovation.”

In a memo to employees on Tuesday, Ryan wrote that “we looked for someone steeped in the courageous journalism that is The Post’s hallmark, and who can extend our reach to news audiences in the U.S. and abroad. We sought a bold leader who can manage our dynamic newsroom and bureaus across the globe . . . We looked carefully for someone who shares our values of diversity and inclusion, and who is committed to prioritizing them in our news coverage as well as our hiring and promotion.”

Ryan said The Post sought a “world-class journalist,” with a particular strength in investigative and political reporting, as well as someone with “the credibility and gravitas” to be an effective spokesperson for the profession. He called Buzbee “an inspiring leader and accomplished journalist in the finest traditions” of The Post.

Ryan said in an interview Tuesday that Buzbee was the “runaway unanimous choice” for the job following interviews with him and Jeff Bezos, the Amazon founder who owns The Post. “We were in total agreement,” he said.

Buzbee was among a small group of candidates who were interviewed by Bezos in Washington last week. Ryan declined to identify others who were considered for the job, citing confidentiality. This is the first executive editor hiring since Bezos purchased the company in 2013.

Buzbee’s appointment was a surprise to those who closely followed the search for The Post’s next editor — a testament to the secrecy in which Ryan conducted his search. Her name rarely came up amid intense internal discussion about who would follow Baron.

In selecting Buzbee, Ryan passed over three journalists who had been considered leading candidates and sentimental favorites among many Post journalists.

The first was Kevin Merida, who spent 22 years at the newspaper, rising to managing editor of news and features, before leaving to join ESPN in 2015. Merida, however, does not appear to have had serious talks with The Post’s leadership in the months since Baron announced that he would step down. Merida was named editor of the Los Angeles Times last week.

The others were internal candidates: Cameron Barr, who replaced Merida as managing editor in 2015 and has been serving as interim executive editor since Baron retired; and Steven Ginsberg, National editor who guided much of the newsroom’s coverage of the Trump White House.

The Post was one of several news organizations that have been seeking to replace their top editors. Among others, ABC News, CBS News, the L.A. Times, Reuters, Wired, Vox and HuffPost are, or were, searching for new leadership in recent months.

After graduating from the University of Kansas in 1988, Buzbee started her career as an AP reporter in Kansas. She was also a reporter in Los Angeles, San Diego and Washington. She made the jump to editing in 1996 as assistant bureau chief in Washington.

Beginning in 2004, she was AP’s Middle East regional editor in Cairo, supervising coverage of the Iraq War. She also holds an MBA from Georgetown University.

Although several women have served as managing editors at The Post, the second-ranking position, none have been appointed to the top spot since the newspaper was founded in 1877. Buzbee joins a line that includes Baron, Marcus Brauchli (2008-2012), Leonard Downie Jr. (1991-2008), and the late, legendary Ben Bradlee (1968-1991).

Buzbee noted the landmark nature of her hiring, saying it was “an honor” to be the first woman in the job. “I’ve always been conscious in my career and my life how others have paved the way for me,” she told The Post. “I’m incredibly grateful for that. I’m also conscious of the fact that we can never rest on the issue of diversity. My feeling is, no matter how much progress we’ve made, it’s never enough.”

In a video meeting attended by hundreds of her new employees Tuesday afternoon, Buzbee avoided speculating about how The Post might change under her leadership. Rather, she said she would listen to staff members and emphasized her focus on “deep, factual journalism” and a newsroom in which “a wide, very wide diversity of voices are heard and have influence.”

News of Buzbee’s hire came as a surprise to journalists inside and outside The Post newsroom, including those who had eagerly followed rumors about the job search. Several noted Tuesday morning that her name hadn’t surfaced in previous news coverage of Baron’s potential replacement.

Much of the public reaction was positive, both from former AP journalists and other reporters who highlighted the historic nature of the hire. AP Washington bureau chief Julie Pace tweeted: “There is simply no better newsroom leader and mentor than Sally.”

“What a long road from Katharine Graham” — former publisher of The Post — “to Sally Buzbee, now The Post’s first woman executive editor,” tweeted Jason Ukman, managing editor of Stat News.

At The Post, Buzbee will assume leadership in a newsroom that was revived under Baron and largely rebuilt by Bezos, who purchased The Post for $250 million from the Graham family in August 2013.

Bezos has made big investments in the company’s technology and newsgathering operations, enabling it to weather the long and continuing downturn in the newspaper business. The heart of The Post’s business success has been its ability to attract digital subscribers; it now has 3 million, triple its total in 2016, but is still well behind its chief rival, the New York Times, and its 7.5 million.

The Post remains one of the world’s most widely read news sites, with 88 million unique visitors in March, according to the ComScore digital tracking firm. The success of its digital operations has cushioned a long slide in print circulation, which now stands at about 200,000 daily and 300,000 on Sunday, both mere fractions of their peak.

Despite the coronavirus pandemic, which punished the already ailing news business, The Post turned an annual profit. Newsroom employees were rewarded in January with New Year’s bonuses of $2,021.

In taking one of the most high-profile jobs in American journalism, Buzbee will inevitably face comparisons to Baron, who guided The Post to 10 Pulitzer Prizes. Baron also faced some internal dissension over his handling of matters involving race and diversity, among other issues.

During Buzbee’s tenure as executive editor, AP reporters won a Pulitzer Prize for international reporting for their coverage of the war in Yemen. That same year, AP’s reporting on the Trump administration’s migrant family separation policy was a Pulitzer finalist.

Buzbee said she plans to relocate to Washington later this month. She has two daughters, Emma, 21, and Margaret, 20. Her husband, John Buzbee, who was a Foreign Service officer and Mideast specialist at the State Department, died in 2016.

Elahe Izadi contributed to this report, which has been updated with more information about Buzbee’s hire.

CORRECTION: An earlier version of this article said The Washington Post is 144 years old. It is 143 years old. The article has been corrected.