Elizabeth Eva Leach is a British musicologist and music theorist who specializes in medieval music, especially that of the fourteenth century. Much of her scholarship concerns the life and work of Guillaume de Machaut.
Leach is a professor of music at St Hugh's College, Oxford (a constituent college of the University of Oxford), where she lectures on the music of Guillaume de Machaut and the trouvères. She has written extensively on Machaut as well as birdsong and nature in the medieval music. In 2016 she was elected as a Fellow of the British Academy.
Leach's major publications include and , which received the Phyllis Goodhart Gordan Prize from The Renaissance Society of America. Music historian Alice V. Clark remarked that Leach's Guillaume de Machaut: Secretary, Poet, Musician will become will "likely become the standard monograph study of MachautâÂÂs life and works".