He was principal conductor of the Oldenburgisches Staatstheater (1936–1939), Vienna State Opera (1939–1943), and Berlin Städtische Oper (1943–1946).
Born in Witkowitz, Moravia, Leopold Ludwig was trained as a pianist at the Vienna Conservatory where he was a pupil of Emil Paur.
In 1936 he became music director of the Oldenburgisches Staatstheater and concurrently was a frequent guest conductor at the Berlin State Opera.
The first of these was at the Edinburgh Festival in 1952 when the HSO presented the British première of Hindemith's Mathis der Maler.
From 1958 through 1969 Ludwig was a frequent guest conductor at the San Francisco Opera (SFO); beginning his appearances in San Francisco with a double bill performance of the United States premieres of Carl Orff's Carmina Burana and Orff's Die Kluge on 3 October 1958.