Pope Francis said the church "isn't afraid of history" and Pope Pius XII's legacy has been treated with "some prejudice and exaggeration."
The documents will be released on March 2, 2020.
Eugenio Pacelli was confirmed as Pope Pius XII in 1939 and served until 1958. The Vatican typically waits 70 years after the end of a pope's term before opening the archives. Pope Francis has been pressured, however, to make the archives available sooner while Holocaust survivors are still alive.
"For more than 30 years, the [American Jewish Committee] has called for the full opening of the Holy See's Secret Archives from the period of World War II," said AJC inter-religious affairs director Rabbi David Rosen.
The documents will be scrutinized as Pope Pius is considered for sainthood.
The Vatican acknowledges that archived material on Pope Pius XII is in greater demand than previous popes.
"Archivists of the Vatican Secret Archives and their colleagues from other Vatican archives carried out patient work of sorting, annotating and inventorying the many fonds and documents," Bishop Sergio Pagano said.
He added that Pope Pius XII has been "too superficially judged and criticized for some aspects of his pontificate. The documents will allow researchers to learn about him "without prejudice ... in all the realistic scope and richness."