Optically stimulated luminescence (OSL) signals from quartz can be used to determine when sedimentary archives were deposited. OSL dating uses the accumulation of energy stored in a crystal structure to measure time. This stored energy is absorbed from ionizing radiation, and is released (reset) by heat or daylight. The total specific energy (dose) absorbed since the last resetting is measured using OSL, and divided by the rate of storage (dose rate) to give the time elapsed from the last heating or daylight exposure. In this Primer, quartz OSL dating is introduced and the signal resetting processes outlined. We describe the origins and quantification of the dose rate and the daylight-sensitive OSL signal most appropriate to dose estimation. The most widely used dose measurement method is then discussed, together with quality-control procedures. A broad set of geological and archaeological studies are used to illustrate the wide range of potential applications, and we describe the challenges arising from different deposition environments and summarize evidence for the precision and accuracy of published ages. Uncertainties and minimum reporting are discussed together with methodological limitations, particularly when applied to young and old sediments. Finally, we highlight the anticipated future developments in the field.