Rosenberg Case, a controversial spy trial in the United States in the 1950's. Julius (1918–1953) and Ethel Rosenberg (1915–1953), husband and wife, were accused of conspiracy to commit espionage for the Soviet Union. They allegedy furnished vital information on the atomic bomb to Soviet agents during World War II. The trial was held in New York City in March, 1951. The Rosenbergs were found guilty, and were sentenced to death by Judge Irving R. Kaufman. They were electrocuted at Sing Sing Prison in New York on June 19, 1953. They were the only American civilians ever executed for conspiracy to commit espionage.

Another defendant in the case, Morton Sobell, a friend of Julius Rosenberg's, was sentenced to 30 years in prison. Evidence against the Rosenbergs was furnished by David Greenglass, Ethel's brother, who was tried separately as a co-conspirator and given a 15-year sentence.

Julius Rosenberg and Ethel Greenglass were natives of New York City. They were married in 1939. He was an engineer and was dismissed from a civilian job with the U.S. Army Signal Corps in 1945 because of Communist affiliations. David Greenglass, who had worked as a machinist at the Los Alamos atomic-bomb laboratory during World War II, admitted supplying secret information to Rosenberg.

The Rosenbergs' trial was held during a time of rising fear of Communist subversion in the United States and provoked intense controversy. For two years after their conviction, the Rosenbergs proclaimed their innocence and sought clemency. They had support from Communists and civil libertarians and humanitarians in many countries. Some supporters charged that the government had tampered with the evidence; some maintained that the death penalty was unwarranted (a view generally held today).

It is the concensus among historians that the Rosenbergs probably were guilty of passing information to the Soviets. However, it is believed that Ethel was far less involved than her husband.