This paper reports on the development of an in situ ultrasonic velocimetry technique, to study the settling and sedimentation behaviour of particle dispersions. Specifically, the technique utilises a commercial ultrasonic velocity profiler (UVP) equipped with a 1 MHz transducer-receiver, to measure both particle velocities in the dispersion and the evolution of the sediment bed interface with time. It was found in systems of bi-modal non-coagulated glass particles (with a major size-peak of ∼10 μm) that measured velocities suggested dispersion segregation, although generally values were not reliable as particle settling velocities were below the instrument's threshold. For particle systems coagulated in 1 M KCl, measured dispersion velocities were within the machine's resolution and a high level of system detail could be extracted from the velocity profile maps, such as the development of hindered settling above the bed and movement of the cloud-front. For both coagulated and non-coagulated dispersions, the evolution of the sediment bed height with time could be measured, by analysing particle velocities in the near-bed region. Bed profiles indicated the non-coagulated particles settled slowly into a compact bed, while the coagulated particle-aggregates initially settled faster into a loosely packed bed that compressed over-time.