In the last 3 decades or so, digital technologies have penetrated into a vast array of human activities; smartphones, computers, Internet, social media, and the rest have not only reached into many domains of everyday life but also spread globally and very rapidly—at a speed that technologies from previous eras had not done. In this special themed issue of the American Journal of Preventive Medicine, a series of papers explore some of the implications of digital technologies for disease prevention and public health.