Gerald Rothberg originally put together the magazine under the name Hullabaloo in 1966, before changing the name to Circus in 1968. Since then he has been the publisher and editor-in-chief of the magazine. In its early years it covered hard rock acts like The Doors and Grand Funk Railroad. Later, Circus began to cater to teenage boys focusing mainly on the popular rock acts of the time. In the late 1970s, the magazine started focusing on pop culture as a weekly in the vein of People Magazine, which caused a drop in sales. The magazine shifted to Heavy Metal acts in the early 1980s, then focusing on glam metal groups like Bon Jovi and Def Leppard in the mid-to-late 1980s. Until the arrival of grunge, Circus prospered in this style. When grunge did arrive, however, the magazine lost focus and sales again dropped.
As the 1990s progressed, Rothberg changed the longtime design and logo of the magazine, pared the staff down to a bare minimum, and started using stories from freelancers. Before the magazine was shut down, Circus covered contemporary heavy metal, competing against magazines like Hit Parader.