Many costume parties use a theme from the past, so you may find yourself looking for 70s fancy dress costume ideas. Often a 1970s party is tied in with the 1960s. Hippie costumes were thought of as a 1960s phenomenon, but they were quite strong in the 1970s. This is a fun costume too with psychedelic colors, flower power and peace medallions. The most popular movie of the 1970s was Saturday Night Fever starring John Travolta. The famous white disco suit is the definitive costume of the era and is recognized by everyone. This is an ideal costume for a 70s party.