Step Across the Border is a 1990 avant-garde documentary film on English guitarist, composer and improviser Fred Frith. It was written and directed by Nicolas Humbert and Werner Penzel and released in Germany and Switzerland. The film was screened in cinemas in North America, South America, Europe and Japan, and on television in the United States, Germany, Switzerland, Austria and France. It was also released on VHS by RecRec Music (Switzerland) in 1990, and was later released on DVD by Winter & Winter Records (Germany) in 2003.

Shot in black and white, the 35mm documentary was filmed between 1988 and 1990 in Japan, Italy, France, Germany, England, the United States and Switzerland, and shows Frith rehearsing, performing, giving interviews and relaxing. Other musicians featured include René Lussier, Iva Bittová, Tom Cora, Tim Hodgkinson, Bob Ostertag and John Zorn.

The film won a "Special Mention" at the European Film Award for Best Documentary in 1990. A companion soundtrack album, Step Across the Border was also released by RecRec Music in 1990.

In January 2020 Cut Up the Border was released on CD by RogueArt. It is a sound collage created by Humbert and French sound designer, Marc Parisotto from over thirty hours of audio tape that were not used in the film.