Although born in America, Keogh was a formidable name in French fashion illustration, graphic design and theatre. Following his first Vogue cover in December 1947, Keogh was to illustrate for French Vogue throughout the 50s and early 60s. His simplified line, most often in dark black ink was spirited and confident bringing an element of surrealism to his art that charmed both clients and audiences. He illustrated for Nina Ricci, Balmain, Schiaparelli, Dior, Balenciaga and Jacques Griffe as well as for the perfumes of Elizabeth Arden and Jean Dessès. In the 1950s Keogh designed the Christmas windows for Galleries Lafayette, Paris. As a graphic artist and set and costume designer, Keogh worked alongside Christian Bérard, Cecil Beaton and Christian Dior at Les Ballets des Champs-Élysées, Paris which at the time was a haven of modernist work producing cutting edge new ballets. Alongside his work in French fashion and theatre, Keogh also designed costumes for film, most notably for the Marlene Dietrich in Kismet (MGM 1944) and Judy Garland and Gene Kelly in The Pirate (MGM 1947).