Leopoldine Konstantin (12 March 1886, Brünn, Moravia, Austria-Hungary–14 December 1965, Hietzing, Vienna, Austria) was an Austrian actress. She took acting lessons with Alexander Strakosch, whom she married shortly afterwards, and made her debut in the Deutsches Theater in Berlin in 1907. She played in Frank Wedekind's Spring Awakening (1907), Shakespeare's Romeo and Juliet (1907), A Winter's Tale (1908), and A Midsummer Night's Dream (1910).
From 1911 she was to be found at the Kammerspielen in Berlin and became known in the Berlin salons. She moved to Vienna in 1916 and by 1924 she was playing the title role in Friedrich Schiller's Mary Stuart.
Starting in 1912 she also played in silent films, initially in title roles. She turned away from this medium when, after the First World War, she was offered increasingly minor parts. In 1923 she had a house built in Westerland for herself and her son Alexander. In 1924 she married Hungarian counsellor and author Géza Herczeg.
From 1933 she returned to film work, and in 1935 she returned to Austria. Divorced in 1938, she moved to the United States via Britain. She spoke no English at that time, and had to take a job as a factory worker until, after intensive language study, she landed a supporting role in Alfred Hitchcock's 1946 film Notorious, in which she played Claude Rains' mother, although she was only three years older than him.
She performed in two television series in 1948 and returned to Vienna. Her last acting work involved sporadic theatre roles and poetry readings on the radio.
- 1912: Gebannt und erlöst (Banned and redeemed)
- 1912: Die Hand des Schicksals (The Hand of Fate)
- 1912: Die Heldin der schwarzen Berge (The Heroine of the Black Mountains)
- 1913: Vater und Sohn (Father and Son)
- 1913: Die Insel der Seligen (The Isle of the Blessed)
- 1914: Kleine weiße Sklaven (Little White Slaves)
- 1914: Die zerbrochene Puppe (The Smashed Doll)
- 1915: Das Wiegenlied (The Lullaby)
- 1917: Aus vergessenen Akten (From Forgotten Files)
- 1917: Der Onyxkopf (The Onyx Head)
- 1918: Lola Montez (Lola Montez)
- 1919: Der Volontär (The Volunteer)
- 1919: Der Verrat der Gräfin Leonie (The Betrayal of Countess Leonie)
- 1919: Können Gedanken töten? (Can Thoughts Die?)
- 1919; Lilli's Marriage
- 1920: Der Shawl der Kaiserin Katharina II (The Shawl of Empress Catherine II)
- 1920: President Barrada
- 1920: Weltbrand (World Brand)
- 1921: Der Silberkönig (The Silver King)
- 1933: Season in Cairo
- 1933: Es tut sich was um Mitternacht (It's happening at midnight)
- 1934: A Precocious Girl
- 1934: Liebe dumme Mama
- 1934: Prinzessin Turandot (Princess Turandot)
- 1934: Der alte und der junge König (The Old and the Young King)
- 1935: Frischer Wind aus Kanada (A fresh breeze from Canada)
- 1936: Mädchenpensionat
- 1936: Und du, mein Schatz, fährst mit (And you, my darling, go with them)
- 1937: Andere Welt (Other World)
- 1946: Notorious
Konstantin in 1917 (with Curt Goetz)