[7][8] After graduating magna cum laude from Harvard University in 2000 in social studies, Leonard began his career as the communications director for John Cranley's campaign for the United States House of Representatives in Ohio's first district.

He went on to work as a columnist for the Trinidad Guardian, an analyst for McKinsey & Company, and an assistant for Creative Artists Agency.

While working at Appian Way in 2005, he came up with the concept behind "The Black List,"[9] forwarding a spreadsheet to seventy-five fellow producers to collect the names of well-known but unproduced screenplays.

[5] Two years later, he was vice president of Creative Affairs at Will Smith's production company, Overbrook Entertainment.

Leonard shared the title with Smith's brother-in-law Caleeb Pinkett, and left the company after two years.