In model driven engineering (MDE), meta-models are the central artifacts. As a complement, the Object Constraint Language (OCL) is a language used to express constraints and operations on meta-models. The Eclipse Modeling Framework (EMF) provides an implementation of OCL, enabling OCL annotated meta-models. Existing empirical studies of the OCL have been conducted on small collections of data. To facilitate empirical research into the OCL on a larger scale, we present the first publicly available data set of OCL expressions. The data set contains 9188 OCL expressions originating from 504 EMF meta-models in 245 systematically selected GitHub repositories. Both the original meta models and the generated abstract syntax trees are included, allowing for a variety of empirical studies of the OCL. To illustrate the applicability of this data set in practice, we performed three case studies.