The actress-turned-director said that the survivors were selected to “share their stories”.
The movie features June Squibb in the leading role as a 94-year-old woman who moves to New York City after suffering a loss.
Eleanor the Great premiered at Cannes Film Festival in May and was released in cinemas on September 26.
Johansson, whose maternal family is Jewish, discovered in 2017 that relatives died in the Warsaw Ghetto during the Holocaust.
She called out the alarming rise in antisemitism in a recent interview with Israel’s Channel 12 News, discussing concerns that it could lead to physical violence.