Una psicoanalista britannica, nata in Austria, che ideò nuove tecniche terapeutiche per bambini, lasciando un impatto significativo sulla psicologia infantile e sulla psicoanalisi contemporanea. Fu una delle principali innovatrici nella teorizzazione della teoria delle relazioni oggettuali.
She made possible the extension of psycho-analysis to the field of early childhood, and in this way not only made the treatment of young children possible but also threw new light on psychological development in childhood and on the roots of adult neuroses and psychoses.
Melanie Klein's writings, particularly on infant development and psychosis, have been crucial both to theoretical work and to clinical practice. 'Envy and Gratitude' her last major work, introduces her theory of primary envy.