Johnny Rosza was born and raised in Nairobi to Jewish-Hungarian/Czech parents. He later moved to England where he went to Repton.
Rozsa studied architecture, painting, and communications at Manchester University, and communications at Polytechnic of Central London. Afterwards, he interned at Vogue under Grace Coddington. He later ran a vintage shop called Nostalgia in Covent Garden, where he met fashion editors, models, actors, and photographers on a daily basis.
In the mid-1970s Rozsa began his photography career, working in Nairobi, Geneva, England, and the U.S. By 1978, he had a series of four full-page celebrity portraits in Ritz, with accompanying interviews.
Rozsa has now been photographing celebrities such as Hugh Grant, Halle Berry, Janet Jackson, Nicolas Cage, John Malkovich, and Natasha Richardson for over three decades. His photographs have appeared in numerous publications, including Vogue, the Sunday Times, i-D, Maxim, The Face, The New York Times, Newsweek, New York Magazine, and People. His portraits of Ian Charleson, Sade, Marilyn, and Martin Degville are part of the permanent collection at the National Portrait Gallery in London. His photographs of Leigh Bowery have been exhibited in several museums, including the Museum of Contemporary Art in Sydney, the Kunsthalle in Vienna, and the Kunstverein in Hanover. Rozsa has also exhibited at the Venice Biennale.
In 2010 Rozsa published a book, Untouched, featuring unretouched photos of 115 now world-famous celebrities, from their days before airbrushing, PhotoShop, digital cameras and enhancements, cosmetic surgery, and perfect images. The book has a foreword by Susan Sarandon, and launched at Barneys in New York City.