She was born on 24th November 1922, in Bydgoszcz. She was a theatre and film actress, as well as a voice-over actress and a private elocution tutor.
During the Second World War, she served as a liaison officer and a nurse. In addition to her activities as part of the resistance, she took acting lessons under the tutelage of Zofia Małynicz and Henryk Ładosz, at the Central Welfare Council in Warsaw.
In 1948, she graduated from the National Higher School of Theatre in Warsaw, which has its headquarters in Łódź. She performed in two theatres located in Łódź, namely the Polish Theatre (later renamed to the Stefan Jaracz Theatre) (in the years 1947-1979), and then at Teatr Nowy (in the years 1949-51). Later on, she started performing at Teatr Powszechny (in 1952), Teatr Syrena (in the years 1952-1955), Teatr Młodej Warszawy (in the years 1955-57), and finally with Teatr Młodej Warszawy (in the years 1957-60). Sometime later, in 1974, Danuta Mancewicz performed at Teatr Polski in Bielsko-Biała, then at the Drama Theatre in Elbląg (in the period from 1975 to 1977), and at the Drama Theatre in Legnica (in the period from 1977 to 1978).
Danuta Mancewicz was most famous as a voice-over actress, who gave her voice to Lolek, one of the characters in the animated TV series for children ,,Bolek I Lolek”, to the characters featured in the TV evening programme for children ,,Przygody Gąski Balbinki”, or to Placek (played by Jarosław Kaczyński), one of the two main protagonists in the film ,,O dwóch takich co ukradli księżyc” / “The Two Who Stole the Moon” (1962).
She was also featured in a number of films, for example in the TV series ,,Strachy” /” Fears” (1979) directed by Stanisław Lenartowicz, the film ,,Szkoda twoich łez” / “Tears Won’t Help” (1983), and in the TV series ,,Rzeka kłamstwa” (1987) directed by Jan Łomnicki. Her very last role on the silver screen was Grandma Bogusia in the TV series ,,M jak Miłość“. The episode featuring her appearance was aired after the death of the actress.
Danuta Mancewicz died on 6th January 2008, in Warsaw.