Heilemann was born in Los Angeles in 1966 and grew up in California. His family was originally from Wisconsin. Heilemann holds a bachelor’s degree in journalism and political science from Northwestern University and a master’s degree from the John F. Kennedy School of Government at Harvard University.

He is the author of a book, Pride Before the Fall, about the Microsoft antitrust case. He has been a staff writer for New York, Wired, and The Economist. He was the host of a four-part documentary series for Discovery called Download: the True Story of the Internet, about the rise of the World Wide Web, which first aired in 2008.

He is the co-author (with Mark Halperin) of Double Down and Game Change, books about Presidential campaigns. He and Halperin co-hosted With All Due Respect, a political analysis show on Bloomberg Television and MSNBC. Heilemann also produced and co-starred (with Mark Halperin and Mark McKinnon) in Showtime’s: The Circus: Inside the Greatest Political Show on Earth, following the presidential candidates behind the scenes of their campaigns in the 2016 United States Presidential Election. Heilemann is producing and co-starring in new episodes of The Circus: Inside the Greatest Political Show on Earth, with Alex Wagner and Mark McKinnon, airing in Spring 2018. Heilemann is also an occasional guest on the Tony Kornheiser Show and MSNBC’s Morning Joe.