Carolyn Reidy, a visionary publishing executive who steered Simon & Schuster through a deep recession and a digital revolution, died on Tuesday in Southampton, N.Y. She was 71.

The cause was a heart attack, a Simon & Schuster spokesman said. At her death, at Stony Brook Southampton Hospital, she was chief executive of the company and one of the few women in the industry to lead a major publishing house.

Ms. Reidy was known for being both tough and generous as she navigated often tumultuous industry shifts over five decades. She was also known for her meticulous engagement with every aspect of the publishing process, from cover art and font type to publicity and marketing.

She became chief executive of Simon & Schuster, one of the Big Five book publishers, in 2008 and immediately faced a challenging economic climate with the onset of the Great Recession and a fast-changing digital landscape. Among her initiatives was the digitization of the house’s backlist.

Under her leadership, Simon & Schuster published a broad range of successful and influential writers, many of whom she championed, including Pulitzer Prize winners like Doris Kearns Goodwin and David W. Blight, best-selling novelists like Stephen King and Jennifer Weiner, public figures like Hillary Clinton, and children’s and young-adult writers like Jason Reynolds.

Bob Woodward, who had known Ms. Reidy for nearly 30 years, called her the “ultimate boss.”

“She would let you write the book you wanted to write,” he said in a phone interview. “She would say, ‘If that’s the truth as you found it, we will publish it.’ There was never any adjustment or political bending.”

Carolyn Judith Kroll was born on May 2, 1949, in Washington to Henry and Mildred (Menckie) Kroll and grew up in Silver Spring, Md. Her father ran a commercial insurance agency.

She attended Middlebury College in Vermont, where she met her future husband, Stephen Reidy, and graduated with a bachelor’s degree in English in 1971. She earned a master’s degree in the subject from Indiana University and completed her Ph.D. while climbing the publishing ranks, writing her dissertation during vacations.

Ms. Reidy is survived by her husband and three siblings.

She began her career at Random House in 1974, in the subsidiary rights department. She sat outside the office of Toni Morrison, who was an editor in the trade book division at the time and who, by Ms. Reidy’s account, proved to be an inspiration. She later worked for William Morrow and Avon Books before landing at Simon & Schuster in 1992, first as president of the trade division and then as head of adult publishing.

Nan Graham, the editor in chief of Scribner, an imprint of Simon & Schuster, said Ms. Reidy had displayed a keen ability to connect writers to “the whole infrastructure of a business that she knew every inch of.”

Mr. King recalled in an interview that after Ms. Reidy took the helm in 2008, the rise in e-books had prompted retailers like Walmart and Amazon to slash the price of physical books, and Mr. King was concerned about how his recently published novel “Under the Dome” would fare in that climate. Ms. Reidy, he said, invited him to her office, gave him tea and patiently explained what had happened and where she saw the publishing industry going.

“She was clear and concise,” Mr. King said. “She was right about a lot of things, and guided the company through some extremely stormy waters.”

Jennifer Egan, the president of PEN America and a Simon & Schuster author, said Ms. Reidy’s commitment to championing marginalized voices had “expanded the literary universe of countless writers and enriched American culture.”

ViacomCBS, Simon & Schuster’s parent company, announced in March that it would sell the publishing company as it pivoted to streaming and other areas.

Ms. Reidy once described herself as a “meddler,” because she enjoyed being involved in every aspect of the company. But Jonathan Karp, the president and publisher of Simon & Schuster’s adult publishing, said he had seen things differently.

“By showing us that she cared about the smallest details,” he said in an interview, “she wanted all of us to care about the smallest details, because she knew that those details can often be the reason a book succeeds.”

Ms. Reidy had a reputation as a fierce advocate for her company and its employees. Mr. Karp, who was hired by her in 2010, recalled an agent once telling him, “All of you people at Simon & Schuster, you wield Carolyn like a cudgel.” When he told Ms. Reidy what the agent had said, she was “delighted,” he said.

He described Ms. Reidy as always intellectually curious. Working with her, he said, “you were engaged in a substantive ongoing conversation that was respectful and nourishing.”

“We’ve been in touch via email virtually every day for 10 years,” Mr. Karp added. “It’s been one of the longest and most enriching conversations of my professional life.”