Born and raised in Hamilton, Ontario,[1] Johnson earned a Bachelor of Arts (BA) in history from McMaster University and completed the Community Shift Leadership Program from Ivey Business School at Western University in London, Ontario.
[2][3] Johnson began his career in the non-profit sector, where he worked on homelessness and poverty reduction initiatives.
[1] In 2010, Johnson was recruited to join the City of Hamilton by City Manager Chris Murray,[4] where he would work in a number of roles including as the director of neighbourhood and community initiatives, the city's corporate initiatives, the light rail transit (LRT) project, eventually becoming the general manager of healthy and safe communities.
He also oversaw the launch of the Toronto Community Crisis Service, a non-police based crisis intervention pilot program, and worked on the city’s bid to co-host the 2026 FIFA World Cup.
[7] On December 2, 2022, Mayor John Tory announced that Johnson was selected to become Toronto's city manager.