Prince Stanisław Albrecht "Stash" Radziwiłł (21 July 1914 – 27 July 1976) was a scion of the Polish princely House of Radziwiłł, born in Szpanów in the Volhynian Governorate of the Russian Empire (now Szpaniv, Ukraine).

His parents were Janusz Franciszek, Prince Radziwiłł (1880–1967) and Princess Anna Lubomirska (1882–1947). Stanisław had two elder brothers, Edmund Radziwiłł (1906–1971) and Ludwik Radziwiłł (1911–1928). His mother, who also came from a Polish noble family, died in a Soviet labour camp. Through his father, Stanislaw Albrecht was second cousin twice removed of Sophie, Duchess of Hohenberg, wife of the Heir to the Austro-Hungarian throne Archduke Franz Ferdinand of Austria.

Marriages

Radziwiłł married Countess Rose de Mouleon (1913–1996), on 10 April 1940 and they were divorced in 1945. She later married Baron de Chollet, a Swiss banker.

Radziwiłł married Grace Maria Kolin on 2 May 1946. They were divorced in 1958. The marriage produced one son:

• Prince Jan Stanisław Albrycht Radziwiłł (8 August 1947), who married Eugenia Carras on 14 September 1978. They have two sons:
  • Prince Jan Michal Radziwiłł (29 August 1979)
  • Prince Filip Radziwiłł (4 February 1981)

Kolin later married William Ward, 3rd Earl of Dudley (1894–1969) as his third wife, and from 1975, she lived with Robert B. Silvers.

Radziwiłł married Caroline Lee Bouvier Canfield on 19 March 1959. They had two children:

• Prince Anthony Radziwiłł (4 August 1959 – 10 August 1999). He married Carole Ann DiFalco on 27 August 1994.
• Princess Anna Christina "Tina" Radziwiłł-Arancio (18 August 1960). She married Octavio Arancio in September 1999; they were divorced in 2005.

Later life

Radziwiłł was one of the organisers of the Sikorski Historical Institute in London and founder of St. Anne's Church at Fawley Court, the site of Divine Mercy College, a school for boys of Polish origin, set up by the Marian Fathers in 1953 near Henley-on-Thames, England.

He died on 27 July 1976, in London at the age of 62. His body was interred in the crypt of St Anne's Church at Fawley Court. 

As of 2010 the Marian Fathers were seeking authorisation to exhume the body following the closure of Divine Mercy College (in 1986) and the sale of Fawley Court (2010).

Title

Upon becoming a British subject and in keeping with standard practice, Radziwill would have needed permission to use his princely title from Queen Elizabeth II, but did not receive special dispensation and was known in Britain as Mr. Radziwiłł legally and as Prince Radziwiłł by courtesy.