John Cioffi (born November 7, 1956) is an American electrical engineer, educator and prolific inventor who has made contributions in telecommunication system theory, specifically in coding theory and information theory. Best known as "the father of DSL,"Cioffi's pioneering research was instrumental in making digital subscriber line (DSL) technology practical and has led to over 400 publications and more than 100 pending or issued patents, many of which are licensed.