The Phoenix was founded in 1965 by Joe Hanlon, a former editor at MIT's student newspaper, The Tech. Since many Boston-area college newspapers were printed at the same printing firm, Hanlon's idea was to do a four-page single-sheet insert with arts coverage and ads. He began with the Harvard Business School's newspaper, The Harbus News. A student there, James T. Lewis, became Hanlon's advertising manager.

Boston After Dark began March 2, 1966. Theater enthusiast Larry Stark began contributing theater reviews with the second issue. When the insert idea did not pan out, the trio continued Boston After Dark as a weekly free paper.

A year after the launch, Hanlon sold off his half to Lewis. For three years, Boston After Dark kept the four-page format, with Lewis as publisher, Jane Steidemann as editor, Stephen M. Mindich as ad salesman and Stark as full-time theater critic and copy editor, plus film reviews by Deac Rossell, who later went on to become head of programming at London's National Film Theatre.

Arnie Reisman was appointed executive editor beginning in November 1968 and ending in November 1971. During Reisman's term of office, what began as Boston After Dark, a 16-page entertainment weekly was turned into a 156-page news weekly on the order of the Village Voice.