For Kamau Witherspoon, it was the night that police arrived at his Minneapolis home, guns pointed at him, shortly after a jog. For Mike McGrew, it was the realization that a manager was tailing him as he shopped at a store supplied by the company where he’s an executive. For Kim Seymour, it was the way she instinctively holds merchandise aloft in clothing stores to make it clear that she’s not shoplifting.

After years of keeping silent, many top black executives are for the first time sharing their experiences of racism widely with their co-workers and employees. Since the killing of George Floyd and protests sparked a national conversation about race and society, many black business leaders say they feel the time has come to open up to colleagues about the difficult, sometimes traumatic encounters they face in the world outside work.

These experiences stayed private, some said, out of concern that calling attention to their race would hold back their careers or that white colleagues wouldn’t understand or listen. While some black leaders are still choosing to keep their personal lives out of the work sphere, others said they feel compelled by the moment. Black people are dying disproportionately from coronavirus. A series of unarmed black people have been killed by police. An unusually graphic video documenting the last minutes of Mr. Floyd’s life has gone viral.

Mr. Witherspoon, senior vice president of operations at Target Corp., had just returned from an early-evening jog and was loading the dishwasher when he noticed flashlights in his window. His heart began racing, until a floodlight switched on. Four police officers were standing in his backyard. When Mr. Witherspoon reached for his window to talk to them, three pointed guns at him. He told the story of the incident, which happened in 2008, at a meeting with about 200 fellow Target executives earlier this month.

“I was standing behind my kitchen sink with my hands up,” he recalled. “It was prompted by a neighbor saying there was a suspicious black guy running through the neighborhood,” he said he later found out.

Mr. Witherspoon, 46, a former Navy officer with an M.B.A., wanted his co-workers to hear directly from someone they know. “The education, the degrees, the fact that I’m a veteran—none of it matters,” he said. “I’m a black man and someone could perceive me as a threat.”

Kamau Witherspoon, senior vice president of operations at Target Corp.
PHOTO: RAYON RICHARDS FOR THE WALL STREET JOURNAL

The world-wide protests against racism and police brutality have sparked a wave of activity from big businesses, which have issued statements condemning racism, pledged millions to support black communities and, at some firms, vowed to hire and promote more black executives into leadership roles.

Black people make up 12.4% of the U.S. population, but only 8% of professionals, a number that has stayed steady since 2013, according to a study by the Center for Talent Innovation, a nonprofit research group. Only 3.2% of senior executive positions are held by black people. Some black executives said that they felt a sense of responsibility to use their platforms for people who don’t have one, and that their goal was to change perceptions in a way that someone without their position may not be able to.

“For Black America, this is a reckoning moment,” said Crystal E. Ashby, interim president and CEO of the Executive Leadership Council, which represents over 800 black corporate executives and board members in the U.S. and abroad. “They have been pushed so far against the wall that they don’t have any choice but to help people understand what this feels like through their lens.”

‘A Burden’

There was a silence during a June 2 videoconference call when Constellation Brands Inc. Chief Executive Bill Newlands opened the floor to about 60 of his executives and staff, asking them to share their thoughts on Mr. Floyd’s killing.

Mr. McGrew, 46, Constellation’s communications chief and the only black member of the executive team at the beer and wine maker, spoke up about an experience he had the previous summer. He had been pushing a shopping cart around a store that Constellation supplies in the affluent Chicago suburb where he lives.

Wearing shorts and a T-shirt, he selected six bottles of wine. Then he noticed the store manager trailing him through the store, as if he were a potential shoplifter. On the call with his colleagues and boss, he said he was tempted to identify himself as a Constellation executive, but instead paid and left.

In an interview, he recalled how he became emotional on the call as he explained it was the kind of experience he had been having his entire life.

Mr. McGrew hadn’t ever shared a personal anecdote of that nature at work, but “as an African-American leader in this business,” he said he felt a duty to “help people understand stuff that they didn’t understand before.”

Target’s Mr. Witherspoon said he opened up not for himself, but to prompt lasting change at the company, telling the other executives, “I’m sharing this story with you to get you to understand how significant of an issue it is, how much of a burden that I carry, the black leaders and team members carry in our stores....We’re exhausted, and this is why we’re exhausted.”

Jill Sando, Target’s chief merchandising officer, who was in the audience, said hearing his story moved her to educate herself about racial inequity. “Never in a million years would I have guessed that Kamau had this experience,” she said. “It’s so fundamentally wrong.”

This month, Target promised to invest $10 million in black communities, provide consulting to black-owned businesses and create a task force to drive racial equity at the company and more broadly. Target said it has been hosting listening sessions for employees for four years, but the largest one took place following Mr. Floyd’s killing and involved 7,000 employees.

‘Unwritten Rules’

After hearing another person tell her story at a company forum, Courtney Dornell, 41, executive director of sales and marketing for the Americas at Otis Elevator Co., decided that, for the first time, she would tell her own. She wrote an essay, shared on LinkedIn, about what she considered the “unwritten rules” of being a black professional in corporate America—don’t stand out, don’t wear bright clothing, don’t gather in groups of more than three.

She wrote about a work trip in China, where she said staff at a restaurant made gorilla gestures and noises at her, while her colleagues didn’t even notice it was happening. Later, when she told some of them, they were horrified and vowed never to patronize the restaurant again.

Sharing the story with her wider professional circle was met with support—including from Otis CEO Judy Marks, who wrote, “Courtney thank you for sharing your personal journey. We are listening and we are learning.”

“I have been with this company for 18 years,” Ms. Dornell said. “These are people who really know me, but they didn’t really know my experience.”

Jide Zeitlin, chairman and CEO of Tapestry Inc., which owns fashion brands Coach, Kate Spade and Stuart Weitzman, recently wrote a memo to the firm’s about 18,000 employees. It details a summer he spent in apartheid South Africa in his 20s and how a political gathering turned violent with armored vehicles, tear gas and rubber bullets.

“I sat down several times to write this letter, but stopped each time. My eyes welling up with tears. This is personal,” starts the memo.

Mr. Zeitlin, 56, said he consulted with other Tapestry executives who discussed the possibility of softening the letter, which states “Black Lives Matter” in bold type, before posting it publicly this month. Mr. Zeitlin resisted, despite realizing he could face blowback.

“If you can’t speak to your conscience at a moment such as this, when can you?” he said. “If there are some that are upset by that, or disquieted by that, so be it.”

Many employees and customers offered their own personal stories and expressed gratitude to him for speaking up, though some complained that he dismissed the looting that occurred at stores. A few threatened to boycott and stopped following Tapestry brands on social media.

Mr. Zeitlin said his main focus now is to drive change and challenge companies that issued buttoned-up statements—without mentioning words such as racism or black. “Until you acknowledge the reality, it’s awfully hard to talk about how you are going to lead change,” he said.

For Mark Mason, 51, chief financial officer at Citigroup Inc., it was his teenage son who spurred him to speak up. “You’re the CFO of the entire bank,” his son said, according to Mr. Mason. “If you put something out, people will read it.”

He warned Chief Executive Michael Corbat he planned to write something “raw.” Mr. Corbat assured him he had his back. Mr. Mason addressed the issue of police brutality in a blog post on May 29 about what it was like to watch the video of George Floyd’s killing, opening it by repeating “I can’t breathe” 10 times, the words Mr. Floyd said in the video before dying.

Citigroup's Chief Financial Officer Mark Mason with his son Mark, Jr.	Jide Zeitlin, chairman and CEO of Tapestry Inc.
PHOTOS: YOLANDA PEREZ; TAPESTRY INC.

“Even though I’m the CFO of a global bank, the killings of George Floyd in Minnesota, Ahmaud Arbery in Georgia and Breonna Taylor in Kentucky are reminders of the dangers Black Americans like me face in living our daily lives,” he wrote. “Despite the progress the United States has made, Black Americans are too often denied basic privileges that others take for granted.”

Sara Wechter, Citi’s head of human resources, said she teared up and could only think, “wow,” when she read Mr. Mason’s words. “Mark is a very private individual and a private leader,” she said. “Writing something like that must have been tremendously painful.”

She said Citi invited its entire 200,000-person global workforce to a Zoom call in which Mr. Corbat discussed his long friendship with Mr. Mason—the two had played golf together and knew each other’s families well. Mr. Corbat said he had always considered himself colorblind, but told employees he regretted not asking Mr. Mason more questions about his life, Ms. Wechter said.

“Even our CEO was willing to say he probably got parts of this wrong, and it’s OK to get parts of this wrong,” she said.

Since the post, Mr. Mason said many colleagues have asked him what they can do to help. He said he has proposed ideas, but also emphasized that relying only on black executives won’t be sufficient. “There aren’t enough of them in most companies to change the fabric of the organization,” he said.

‘Put Up This Wall’

Nathaniel Patterson, Jr., 64, a leadership coach who serves on board of the Mobile Area Chamber of Commerce and other nonprofits, didn’t even tell his mother about the time he was 14 years old and walking home from school when a police officer pressed him up against a car and asked what he was doing in the neighborhood.

“When I didn’t answer, he threw me to the ground and put the gun in my mouth,” he said. “He told me that ‘I could kill you’ and nobody would blame him. He told me that before I could go, I had to suck on the barrel.”

He buried it away from his colleagues during his years as a marketing executive and later running his own marketing firm until earlier this month, when he told the story in a LinkedIn post to hundreds of contacts and colleagues. “You put up this wall,” he said. “If you are labeled as a person bringing up the race card, you are going to have your career blocked.”

Cara Robinson Sabin, CEO of Sundial Brands.	Nathaniel Patterson, Jr., a leadership coach who serves on board of the Mobile Area Chamber of Commerce and other nonprofits.
PHOTOS: SHEAMOISTURE; PATTERSON FAMILY

Lynnwood Bibbens, 48, the co-founder and CEO of streaming video network ReachTV, said he never brought up his run-in with police to his wider professional network before. “You hear people saying already that black people think they are victims,” he said.

On June 2, he wrote a letter—opening with “Dear America”—describing the 2004 encounter with police officers who pointed a gun at his head after pulling him over in his Mercedes. He said they held him in handcuffs for nearly an hour on the side of the busy street in Cherry Hill, N.J., near the office where he ran a business with 40 employees. Police later told him that his car matched the description of a stolen vehicle.

“I honestly thought I was going to die; I thought about the things I wanted to tell my son and wouldn’t have the chance,” he wrote in the letter posted on Instagram and later on LinkedIn.

According to the police report, the license plate had been incorrectly entered by another police department as stolen.

“There’s a lot of white people that look at me and a lot of successful black executives as not ‘black,’” Mr. Bibbens said. “They see black people on TV, and they see me, and they say, those are two different types of black people. They can’t have similar experiences. They must have done something different. The truth is, we have similar experiences.”

Cara Robinson Sabin, 50, the CEO of Sundial Brands, said employees at the beauty company, which focuses on black shoppers, were already having candid conversations about race. Those conversations are now happening at other brands owned by Unilever PLC, which acquired Sundial Brands in 2017. The depth of the conversations feels different this time, she said.

The pandemic—and the fact that many people are working remotely, sharing their stories in video chats and conference calls—is making it easier for some to open up, Ms. Sabin noted, adding: “There’s something about looking at people’s faces on video that feels more intimate.”

‘A Turning Point’

After he saw the Floyd video, J.D. Redmon, a 29-year-old vice president of marketing at TTN Fleet Solutions, said he couldn’t sleep or concentrate on his job at the trucking-software company in Argyle, Texas. He decided to post a seven-minute video on LinkedIn to urge his co-workers to call out racism and to share his own encounters, including a painful childhood memory of white neighbors moving away when his family moved nearby.

“I was fully prepared to wake up the next day without a job,” he said.

A few days later, Mr. Redmon’s employer asked him to speak on a Zoom call where other black employees told stories of their own. “It was actually a turning point for black employees at my company,” he said. “I think they felt comfortable speaking up because they saw how I was being embraced by my peers.”

After he posted another video on Juneteenth pointing out that the trucking industry is led mostly by white men, he said some people inside the company told him he needs to be careful about not offending anyone and warned him that LinkedIn is a professional site, and not for personal views.

But his boss, Tyler Harden, an executive vice president, sent him a text: “Don’t ever let anyone or anything change you! That is not a request!”

“If being me costs me my job, so be it,” Mr. Redmon said.

Kim Seymour, 50, chief people officer at WW International Inc. (formerly Weight Watchers), said she has long been vocal on issues of race, equality and inclusion as a human-resources professional and became even more so after some cancer scares.

After the killing of Mr. Floyd, she said she immediately felt compelled to post a message to employees on WW’s internal social-media network about racism and Black Lives Matter. “I’m prepared for someone to be offended by this,” she wrote in a post she later put on LinkedIn. “I’m lucky that my leader is not one of them,” referring to WW CEO Mindy Grossman.

Ms. Seymour said she still finds herself accommodating bias in daily life. She instinctively raises her merchandise high in the air when she goes shopping in a department store so that store workers know she’s not stealing.

She said she believes most black executives in her generation have succeeded in a similar way, going out of their way to make white people feel comfortable around them. Many in her cohort feel they can only tell the truth after reaching a certain level, she said, but younger employees aren’t waiting for that moment. “Now more people are getting there and getting there faster, willing to risk the comfort of their positions for the power of their convictions,” she said.

After recently becoming a partner in PricewaterhouseCoopers LLP’s deals practice, Crystal Wright, 38, said she has allowed herself to become more vulnerable with co-workers by expressing the fear she feels for her husband and what it would mean for her family—she has a 16-month-old son—if she were to lose him.

She said the U.S. chairman of the firm, Tim Ryan, has created a platform to talk openly about the topic of race, and white employees are sharing their stories, too. One of her white co-workers recently told her that he’s trying to talk with his children about race and how interactions with the police might be different for people of color.

She said she hopes employees will also become more candid about their experiences within their own companies. “An issue with the police is one story, but it’s another thing to listen to someone tell a story that ‘I feel like I didn’t get a promotion here because I was discriminated against,’ ” she said. “If we want change within corporate America, those conversations are pivotal.”

—David Benoit and Jennifer Maloney contributed to this article.