Leonie is a Latin-origin feminine given name, (meaning "lioness"), from the masculine personal name Leon (meaning "lion"). Leonie evolved to Léonie in France. It is rare as a surname.[2][3]

The name Leoni/Leonie also derives from the Greek name Leonidas. It is commonly used in Greece, but with a different pronunciation than in English.

In Eastern Orthodox Christianity there are several saints named Saint/Agios Leonidas. Therefore a child born into orthodoxy would have their name day (religious celebration m. See: name day) People with the name or its variants would celebrate on the day the Saint was killed.

People with the name or its variants include:

S. Leonie Brown (1963), Doctor of Education and Writer