The grant is projected to create space for 1,500 preschoolers in quality centers by 2021. Kenney's goal is 10,000 new quality seats in Philadelphia over the next five years.
"The research is really clear that investing in early childhood education is one of the most productive investments you can make," said Laura Sparks, executive director at the foundation.
The grant money will go into the Fund for Quality, a local initiative that provides financial and planning assistance to high-quality early childhood centers citywide.
William Penn gave $4.6 million to the fund when it was created in 2014.
Kenney has said part of the goal for universal pre-K is ensuring that children are going to quality facilities, places where they get instruction, not babysitting, with certified teachers in well-kept, resource-rich facilities.
In Philadelphia, only 20 percent of providers are considered "high quality," based on a state certification program. Only these centers will be eligible for the grant money.
Leslie Spina, executive director of Kinder Academy, opened her Northeast location in a shuttered shoe store last year with help from the Fund for Quality.
"This money allowed insulated floors so infants and young toddlers on the floor all day aren't on cold floors," she said. "It paid for sinks and bathrooms in every classroom."
Pre-K providers like Spina operate on extremely thin margins. "It's hard to put aside time or money for expansion, and these folks are experts in educating young children, not facility expansion," said Natalie Renew, managing director for early childhood education at Public Health Management Corp., which operates the Fund for Quality.
Interested providers can apply for help identifying potential sites and appropriate contractors, as well as help navigating city zoning rules.
Anne Gemmell, Kenney's director of prekindergarten, said she hopes the fact that the grant money is available only to quality providers prompts lower-quality centers to improve.
"It feels like a big vote of confidence," Gemmell said. "William Penn has said to us, 'You don't have to do this alone, here we are.' "