An inexpensive and portable device for monitoring personal ozone exposure is described and its performance characterized. The device is built from commercially available components, exhibits time resolution of approx. 60s, and highest analytical sensitivity under 100ppbv ozone. The sensor has been employed to provide insights into ozone exposure for 8 volunteers living in Lubbock, Texas during the winter months of 2015. Consistent with previous literature, the results indicate the volunteers were exposed to highest levels of ozone when outdoors during daylight hours. Exposure to ozone indoors was typically only a fraction (0.3–0.7) of the dose observed during times spent outdoors. The sensing system described requires minimal technical skills to assemble and use at a cost of approximately $150 USD per unit (see Table 1). The device's batteries provide power for 8–10h on a single charge and the sensor can be re-used many times after recharging the battery pack. A major advantage of the sensor over chromogenic filters for exposure monitoring is the collection of time-series data that allows users to better understand when and where individuals are exposed to highest ozone concentrations. The device may prove useful for industries requiring a low-cost solution to monitor employee exposure to ozone for specific work environments.