This editorial presents the Seventh International Conference on Uniform Distribution Theory (UDT 2021), which was organized by Johannes Kepler University Linz and the Johann Radon Institute for Computational and Applied Mathematics (RICAM) of the Austrian Academy of Sciences. Originally planned as an in-person event, the conference was held online due to the COVID-19 pandemic. The article outlines the scientific program, highlights the invited plenary lectures covering topics in uniform distribution theory, number theory, discrepancy theory, finite fields, Diophantine approximation, and related areas, and acknowledges the contributions of the program and organizing committees. It also introduces the invited papers included in this volume of Uniform Distribution Theory, reflecting recent developments and current research directions in the field.