In 1937, he won the Grand Prix du Disque for the song "Vous qui passez sans me voir". Contracted by the producers of The Magic Key, thanks to his success in France, he left for New York, engaged at the NBC studios of Radio City. In Hollywood, Sablon was contracted to star in "The Story of Irene and Vernon Castle" with Fred Astaire and Ginger Rogers. Due to production disagreements, he demanded the withdrawal of scenes in which he starred. The final version conserves merely his interpretation of the song "Darktown Strutters Ball". In the movie capital, he appeared at the Trocadero. He also presented and sang his songs on the radio show Hollywood Hotel on which he invited numerous big stars. In the 1940s his "Jean Sablon Show" was on the Columbia Broadcasting System (CBS) radio and was accompanied by the American accordionist and songwriter John Serry Sr, with Toots Camarata as musical arranger. He returned to Paris to appear on the stage of the ABC and took part to television experiments. Then he returned to  star on Broadway and then Boston in the musical "Streets of Paris". He was teamed him with Carmen Miranda, who appeared for the first time outside of Brazil. Sablon made his debut at the Teatro Municipal in São Paulo in 1940, and then in Argentina, Uruguay and Chile. In 1941, he had further engagements in New York, at the Waldorf Astoria, the Plaza and at the San Regis hotels, before going on, in 1942, in Los Angeles and in Cuba, and then touring in America, Brazil and Argentina. Some of his appearances were for war victims. Meanwhile, in 1943, in London, his sister Germaine was the first to perform Le Chant des Partisans, which became the anthem of the French Resistance. Sablon continued to sing in Brazil, Argentina and Uruguay, appearing there through 1945, when he returned to the US to perform in New York, Chicago and Washington. His 1947-48 US tour took him to New Orleans, San Francisco, Hollywood (Ciro's), Boston, Los Angeles (Beverly Hills) and Palm Beach, and then onto Brazil, Argentina and Canada. Sablon's recording of "Les Feuilles mortes" (Autumn Leaves) in the summer of 1947 in New York (RCA Victor 855332) is the earliest version of this classic.