The ignition delay of a fuel/air mixture is an important quantity in designing combustion devices, and these data are also used to validate computational kinetic models for combustion. One of the typical experimental devices used to measure the ignition delay is called a Rapid Compression Machine (RCM). This work presents UConnRCMPy, an open-source Python package to process experimental data from the RCM at the University of Connecticut. Given an experimental measurement, UConnRCMPy computes the thermodynamic conditions in the reactor of the RCM during an experiment along with the ignition delay. UConnRCMPy relies on several packages from the SciPy stack and the broader scientific Python community. UConnRCMPy implements an extensible framework, so that alternative experimental data formats can be incorporated easily. In this way, UConnRCMPy improves the consistency of RCM data processing and enables reproducible analysis of the data.