The Virtual Symposium on N-of-1 Trials, held in December 2020, brought together international researchers, clinicians and patient advocates to explore the science and application of N-of-1 trials and single-case experimental designs (SCEDs). Hosted by the Icahn School of Medicine at Mount Sinai and the N1 App Research Team, the four-part online symposium covered the history of N-of-1 trials, study design and analytical methods, future directions for the field, and patient perspectives.