Alexandra Mary Theodora (Lex) Radius (born 3 July 1942 in Amsterdam) is a retired Dutch ballerina.
There, in 1959, she met Han Ebbelaar, who would become her husband and lifelong dancing partner.
Her other regular dancing partners were Rudolf Nureyev, Henny Jurriëns and Alan Land.
In 1990, she stopped performing ballet at the age of 48, on which occasion she was awarded the Medal of Honor for Art and Science of the Order of the House of Orange.
The Alexandra Radius Prize for rising young dance talent has been named after her.