The world’s population is aging, especially in developed countries. The audience for most websites, apps, and digital devices includes older adults, so most websites, apps, and digital devices should be designed to accommodate them. Unfortunately, many are not. This presentation is based on a book co-authored (with Kate Finn) by the presenter, Jeff Johnson: “Designing User Interfaces for an Aging Population” (Elsevier 2017). The book is based on an extensive review of the literature, as well as the authors’ experience designing, reviewing, and testing apps, websites, and appliances with older adults. The presentation describes age-related factors that affect older adults’ ability to use digital technology, and offers design guidelines that reflect older adults’ varied capabilities, usage patterns, and preferences.