Dr. Toyin Ajayi: The Nigerian Doctor Who Built a $6 Billion Healthcare Company

Dr. Toyin Ajayi built a nearly $6 billion healthcare company in the United States, not by chasing the richest customers, but by refusing to walk past the people everyone else ignored.

Raised in Nairobi, shaped by the frontlines

Born to Nigerian parents and raised in Nairobi, Toyin Ajayi grew up watching her father, a physician, fight on the frontlines of the AIDS epidemic, caring for the people society often overlooked. That experience shaped the rest of her life.

She went on to study at Stanford, Cambridge and King's College London. She could have chosen the comfortable path. Instead she went to Sierra Leone, where only about 50 doctors were serving nearly 7 million people. She learned something there that stayed with her forever: the people who need healthcare the most are often the ones who receive it the least.

Same story, different country

When she moved to the United States, she saw the same story all over again. Different country, same forgotten people: Medicaid patients, people living with chronic illnesses, communities the healthcare system had quietly given up on. Everyone told her the same thing: "You can't build a successful business serving poor people." She refused to believe it.

Building Cityblock Health

In 2017, she co-founded Cityblock Health, incubated inside Alphabet's Sidewalk Labs, with a simple but radical idea: if you care for the most vulnerable patients before they become critically ill, everyone wins. Patients get healthier, hospitals spend less, and the healthcare system becomes more efficient.

What many dismissed as charity turned out to be one of the biggest healthcare opportunities in America. Today, Cityblock Health has raised nearly $900 million and reached a valuation of almost $6 billion. In 2022, Dr. Toyin Ajayi became its CEO: a Nigerian woman leading one of America's most important healthcare companies.

Where everyone else stopped looking

Sometimes the biggest opportunities are not hidden where everyone is looking. They are hidden where everyone else stopped looking. Stories like hers are why we built BeyondAfrica. Meet the next generation of them in Austin on November 7, 2026, and read more spotlights on the blog.