Until the moment Archer Harman whispered the idea into her ear, Kathleen O’Neill Jamieson had never imagined becoming the head of a school.

A teacher, absolutely. An administrator, certainly. She had already done both in her young career — teaching English at three schools and serving as director of the annual fund and then director of admissions at Princeton Day School in New Jersey. But headship?

Twenty-five years later, Jamieson is sitting in her Head of School office in Hearst Hall as she recounts this story with relish. Harman, she says, was the interim head of Princeton Day School when he asked Jamieson to address an influential audience of former trustees. The presentation was so impressive that he leaned in afterward to tell her, “You should be a head of school.”

The comment stuck with Jamieson, she said, because she really admired Harman’s work as a head. “He enjoyed what he was doing, and he was good and kind to people,” she said.

In 16 years as Head of NCS, Jamieson has done much to advance the school’s already considerable reputation as a national leader in education. NCS has expanded its curricular offerings in STEAM disciplines; completed the long-planned renovations to Woodley North; improved its financial model; developed an updated mission statement and, for the first time, clearly stated core values; and enhanced coordination with St. Albans School.

Along the way, Jamieson has lived out qualities that she saw in Harman: She takes pleasure in her work, even when the hours are long. She prioritizes what best serves the students in her charge. And she has made a point of identifying and inspiring a generation of educational leaders: Ten administrators and department chairs have gone from NCS directly to take the reins at schools around the country, while many more faculty, staff, and administrators have held key positions in independent-school organizations.

“One of Kathy’s greatest gifts to education is that she has gotten a whole lot of women to see themselves as leaders who wouldn’t necessarily have done that,” says Sarah Pelmas, who led the NCS Upper School from 2010 to 2016 and now heads the Winsor School in Boston. “I have to tell you that, until the last year I was at NCS, it never would have crossed my mind to be a head.”

Jamieson has been known to give a nudge when she thinks a colleague is looking past a great opportunity. More commonly, though, her style is to show, not tell. Past and present NCS administrators especially credit her flair at making the role of head look like fun in helping them to see their own path to leadership.

“I was getting to watch and experience a seasoned school leader who had so many gifts and talents but also to truly be mentored and supported by someone who I felt wanted to bring out the best in my leadership as well,” says Langley School Head Elinor Scully, who held senior administrative roles at NCS from 2005 to 2013. “I think it’s important, if you aspire to be a head of school, to be in the company of people who are really good at the job and who love it.”

“Kathy takes genuine delight in the success of others, be it students or staff, and she’s a joyful person. That joy is contagious,” recalls Mary Jane McKinven, who was NCS communications director from 2009 to 2015.”And she would see potential where we just might see a wall. She would say, ‘No, you can go through it.’ ”

“She really does trust that people will do a good job,” Pelmas says, “and I think it’s her sense that that’s the best way to help them do a good job is to say, ‘Give it a shot and we’ll see how it goes. I’m here if you need me, but I don’t think you do.’ ”

Jamieson replies to such comments by joking that being a head is easy: Select the right people, then step back and let them work.

But she reflects that, with seven children in the O’Neill house, “the most brilliant thing our parents ever did was convince us that we were responsible for each other’s success. My mother used to call it sibling revelry.”

“I learned early that each of us had a different kind of role and that we all needed to work together to make anything work particularly well,” Jamieson says.

Perhaps, she adds, that is why “I’ve always been comfortable with multiple types of leadership. You need to have adults who not only don’t all look the same but also have different perspectives and ways of operating.”

At the same time, Jamieson has played a quiet but central role on numerous important projects for the school, first by identifying them and then keeping them on track.

One vivid example was the NCS mission statement, which Jamieson wanted to update as part of a strategic planning process in 2011–2012. “That was a hallmark of how Kathy likes to work, in the way she pulls things together,” Scully says. “There was a real sense that everybody’s ideas mattered.”

The final result, “We believe in the power of young women and educate them to embrace our core values of excellence, service, courage, and conscience,” distilled NCS’s identity in a way that students, alumnae, faculty, staff, and Governing Board members would quickly embrace.

Getting to that point, though, took months, and in the end, it required the administrative team to refine the ideas of faculty and staff into one sentence. Jamieson kept urging her colleagues to keep at it, that they were making good progress on their way to something significant and lasting.

“By the end, we were finishing each other’s sentences and phrases,” Jamieson says. “People would go away at night and come back with an idea in the morning.”

Years later, what the administrators remember about the project is less the labor and more the fun they had.

Scully credits Jamieson for recognizing the need “to toggle up to the right altitude to keep a sense of humor and perspective, to be able to reiterate in a way that feels creative and energizing.”

The mission statement also revealed another facet of Jamieson’s character: her conviction that pushing a little harder, giving just a little more when a project feels not quite done or right, will pay off in the end.

“I just like getting things the way they’re supposed to be,” she says.

That combination of optimism and tenacity has played out often at NCS: during the years-long, multi-phase work on Woodley North; the creation of the Teaching and Learning Center and the Center for Ethical Leadership and Service; the adoption of a new block schedule for the Upper School, in coordination with St. Albans; and, most recently, the Upper School’s move beyond Advanced Placement courses.

“Can we stretch? Can we think larger? When you’re caught up in the day-to-day, sometimes such requests feel beyond your grasp, but that is how a leader leads,” McKinven says.

“It was intense. It was fast-paced,” Scully says of her time at NCS. “But, as hard as we worked, we laughed. It was very joyful work.”

Virtually everyone who has worked with Jamieson notes the pleasure she takes from her role, whether it is from engaging with students on the sidelines of a field hockey game or cheering on a teacher’s well-deserved recognition off the Close.

The irony is that, back in 2003, Jamieson declined the invitation to join NCS. She said no, thank you. Twice.

She was leading the Purnell School in Pottersville, N.J., where over five years she had “really helped establish and deepen that school’s national reputation,” says Maret Head of School Marjo Talbott, who has known Jamieson for decades.

“My family was happy,” Jamieson said, “and I was doing interesting work up there.”

When members of the NCS search committee met personally with Jamieson, they told her, Imagine the model you could create at NCS, with support from generations of proud and devoted alumnae; an iconic location in the nation’s capital; and a unique educational relationship with both Washington National Cathedral and St. Albans School.

They persuaded Jamieson to reconsider, and she started at NCS the following July. In October, she brought her vision of the educational model to the entire school community in her installation service, calling it “the most worthy challenge of all.”

In hindsight, it is remarkable how consistently Jamieson has held to principles first defined in 2003: Begin with respect for our students. Focus on their personal development, including social/emotional learning, alongside their intellectual development. Set aside regular time for reflection. Surround the child with adult role models who take care of each other and exemplify the vibrant possibilities available through learning.

If Jamieson’s first address to NCS served as a declaration of principles, the homilies that followed have been opportunities to discuss what drives her as an educator and a leader: Commit to making a difference in the world. Hang onto your summer self. Balance ambition with patience and humility. Be kind. Trust in others. Have faith.

“I have always found with Kathy that she’s someone you want to learn from and share with and trust,” says Talbott.

“So much of the work that you do as a Head is invisible,” Jamieson says, “but it’s important to speak to the community.”

Jamieson believes deeply in the power of language, and a writing assignment tends to grab her attention like little else. It’s a passion that first took hold of her in the 9th grade while she was being punished.

Her English teacher assigned her to write an essay, “Life Inside a Ping-Pong Ball,” for laughing uncontrollably long after others had settled down. The result delighted the teacher, Bob Leslie, and he encouraged her to continue with her writing. “He made me feel that I had some real talent,” Jamieson recalled. “I’ve never forgotten it.”

She became a teacher herself after graduating from college, and at NCS, she returned often to the classroom: She was an Upper School homeroom adviser from 2003 through 2010, and she taught a science-writing elective for several years.

“I very much admired her for teaching science writing,” McKinven says. “The demands with being head of school don’t allow for this, but that class was a labor of love.”

“In a lot of ways, my proudest designation is as a teacher,” Jamieson says. Eventually, though, she would step back from teaching to focus on the duties of being the Head.

“One of the hallmarks of Kathy’s tenure is that she worried much more about doing the right thing than anything else,” Pelmas says, “not what’s the most expedient thing or the politically appropriate thing or any of that.”

In the close of her tenure at NCS, Jamieson has been thinking more about “how we can stand as a model of what family, church, and school can do together. Because, if you look around this community, the volunteers, the service, the philanthropy, the love that’s expressed in worship services, there’s a lot of goodness.”

Her own model of family, church, and school today touches each institution on the Cathedral Close. Jamieson also serves as a canon of the Washington National Cathedral and sits on the management committee of the Protestant Episcopal Cathedral Foundation; her husband of 45 years, Dan, is the associate headmaster for development at St. Albans; her oldest daughter, Katie, teaches 2nd grade at Beauvoir; and two of her seven grandchildren attend NCS and Beauvoir.

Kathy and Dan have not yet decided what lies ahead for them. More time with their grandchildren is high on the wish list, but with the little ones in three different cities, that gets complicated. The Jamiesons still own the Princeton, N.J., house they lived in before coming to Washington, and they have a family getaway in northern Michigan; each has its own attraction. The idea of writing a book has long appealed to her, and now she would have the time to focus on that. And she says she doesn’t feel ready yet to retire from education.

In a 2011 homily, Jamieson told the school that she has been blessed to experience epiphanies “when I am quiet — when I am in the world, but not the center of it. I believe such moments were created by God to capture our imaginations and wills and to inspire us to great commitments of love and compassion on behalf of those who need us.”

Eight years later, in her office, Jamieson said she still is “susceptible to epiphanies, these little moments that are guiding. Bob Leslie was one of those. Archer Harman was one of those.”

So as she thinks about the future, Kathy Jamieson is taking care these days to keep her mind, and her ears, open.