Jeff Hagedorn was born in Milwaukee, and attended Ripon College and the University of Wisconsin, Whitewater. He also took courses at Marquette, University of Wisconsin, Madison, and United States International University, San Diego. While he initially focused on directing, he soon realized his calling as a playwright. After relocating to Chicago, he became a founding member and resident playwright for the Lionheart Gay Theatre. In 1983, his play, One, became the first publicly produced theatrical work concerning AIDS. Hagedorn provided the play to AIDS organizations across the country as a fundraiser, and in the early years of the crisis benefit performances raised more than $50,000. He also formed a production company, SYZYGY, that went on to revive Chicago's pub theater movement with quick witted plays such as The Layman's Guide to Safe Sex. Hagedorn continued to craft seminal AIDS plays as the crisis progressed, from the desperate search for medication in Crusaders, to the challenges of testing in High Risk Romance, and "safe sex" in Should Have Been A Love Play. SYZYGY actors in Chicago performed a marathon of 11 his theatrical pieces in 12 days in 1988.

In a search for greater opportunities, Hagedorn moved to Los Angeles, continuing his community theater work through Celebration Theatre and his production company, SYZYGY. Hagedorn’s theatrical productions were performed in over 32 cities in the United States, and internationally in Edinburgh, Manchester, and Berlin; in addition, he produced and distributed gay themed videos for a gay audience, including Jerker and Dream Man.

Hagedorn dedicated the last years of his life to preservation of gay and lesbian history, organizing the subject files and updating the database of the International Gay and Lesbian Archives, now ONE National Gay & Lesbian Archives.