The Toolbox for River Velocimetry using Images from Aircraft (TRiVIA) provides an end-to-end workflow for mapping velocities in rivers from videos or image sequences. The software includes modules for extracting frames, stabilizing and geo-referencing images, defining a region of interest, enhancing images, performing particle image velocimetry (PIV), visualizing results, assessing accuracy, and calculating discharge. In this introductory session, we will provide a brief overview TRiVIA's capabilities using an example data set from a river in Oregon collected using an uncrewed aircraft systems (UAS). Our target audience is any hydrologist who wants to learn about image-based techniques for estimating flow velocities in rivers.