Brunhilde Pomsel died on January 27th in a care home in the southern city of Munich, said Christian Krönes, who conducted extensive interviews with her for his 2016 film "A German Life".
Pomsel, who worked for Goebbels as a secretary and stenographer for three years, had insisted she had no idea of the Holocaust that claimed the lives of six million Jews while it was happening.
"We knew nothing," she said in the film.
"We ourselves were all trapped in a vast concentration camp," she said, referring to the totalitarian state of Adolf Hitler.
As one of half a dozen secretaries in Goebbels' office, working there from 1942 until the 1945 collapse of the Nazi regime, Pomsel was among the last eyewitnesses to the inner circle of top Nazis.
In "A German Life", she insisted she felt no guilt and also said: "I could not put up resistance - I was too much of a coward."
She told AFP in an interview last year that she had once cheered on Hitler, in 1933, adding that "we didn't know then what lay ahead".
She spoke of the final days in Hitler's bunker, saying a lot of alcohol was drunk because the Nazi chiefs had to "numb themselves".
When Soviet troops marched into Berlin at the end of World War II, Pomsel was captured and would spend five years in Russian detention camps.
From 1950 she worked for a German public broadcaster for 20 years, but kept silent about her war-time job until she gave a newspaper interview in 2011.
'Warning future generations'
She opened up at great length in the 2016 film, which its makers said aimed to force viewers to ask themselves what they would have done, and whether they would have had the courage to resist the Nazi machine.
In the black-and-white film, extreme close-up shots of Pomsel recalling her time with Goebbels are interspersed with archival footage of Nazi horror, including of naked Jewish corpses and mass graves.
Pomsel herself said: "Nothing's black and white. There's always a bit of grey in everything."
"I wouldn't see myself as guilty," she said, "unless you end up blaming the entire German population".
She told AFP in an interview that "since I have a clear conscience for myself, I do not see why I should not talk about it".
She said the point of the film was "for future generations to be informed about all these things. There are ever fewer eyewitnesses left. So I agreed."
She described Goebbels as well groomed and polite, and "an excellent actor," who during public speeches turned into a "raging dwarf … unrecognisable"
But she also labelled him "a very cold person" who showed no interest in the lives of those who worked for him.
Asked about rising right-wing populism in Europe now, she said she found it "horrific, just horrific".
Filmmaker Krönes confirmed to AFP that she died on January 27th in the old people's home but had remained mentally alert until her death.
"We were in contact, I last spoke to her on the occasion of her birthday on January 11th," he said.
"She was still full of energy, full of hope for the future.
"There were some ups and downs owing to her advanced age. Mentally there was no change, she was still alert."
He said a book on Pomsel's reminiscences, based on the interviews, is set to be published this year.
Krönes said that, in view of the rise of right-wing populism in the western world, it was intended "as a warning to current and future generations."