Ms. Dungey grew up in Sacramento — her sister is the actress Merrin Dungey, known for her TV work on “The King of Queens” and “Alias” — and graduated from the University of California, Los Angeles, where she studied film and television. She got her start in Hollywood in the early 1990s, developing movie ideas at 20th Century Fox and then becoming a story editor for Steven Seagal’s company, which was based at Warner Bros. Ms. Dungey soon became a Warner production executive, working on films like “Twister,” “Space Jam” and “The Bridges of Madison County.”

She joined Disney in 2004 as an executive at what was then Touchstone Television, where she helped develop “Criminal Minds” for CBS and played a major role in the early production of “Grey’s Anatomy.” Her dogged advocacy for that medical drama, created by a then-unknown Shonda Rhimes, became an asset as Ms. Rhimes rose to prominence as one of Hollywood’s most important show creators, with hits like “Scandal” and “How to Get Away With Murder.”

Along the way, Ms. Dungey won fans in Hollywood’s broader creative community by delivering feedback in a manner that managed to be both blunt and compassionate. She also became known for a quiet resolve — standing out by not joining other television executives in public grandstanding, even when she made history as the first black network president.

“I’m humbled by the great things that people have said,” Ms. Dungey told The Los Angeles Times in 2016 when she replaced Paul Lee as ABC’s chief. “In terms of looking at this as maybe being a role model, I’ve always been very focused on being a role model for my daughter. And if I can inspire young women to pursue a career path in entertainment because of this, that would be a wonderful thing.”

Ms. Dungey has encountered her share of difficulties — some involving diversity — since taking over as president of ABC Entertainment, a job that gives her oversight of prime-time and late-night programming, marketing and scheduling.

She was criticized (along with Mr. Sherwood) for putting the rebooted “Roseanne” on the schedule in the first place, especially after the uproar over an episode’s joke about the minority-led comedies “black-ish” and “Fresh Off the Boat.” In a blow to ABC, Ms. Rhimes decamped to Netflix in August after the streaming service gave her a lucrative multiyear deal.