This paper addresses the problem of how to represent education information to support the analysis of a city's education system performance. ISO 37120 is standard for measuring city performance. It defines 100 indicators of which seven focus on the Education theme. As cities across the world adopt the standard and begin publishing their indicator values (see dataforcities.org), citizens, city bureaucrats and politicians will be able to see how well their education systems perform relative to other cities. Hence, education systems will be subject to greater scrutiny and will have to provide evidence-based explanations for their performance. In order to enable the analysis of city performance, a city must be able to solve five problems: 1) how is meta-data associated with a single indicator value represented? 2) how are indicator definitions represented? 3) how is the data used to derive an indicator value represented? 4) how is educational system specific knowledge represented, and 5) how is city specific educational system knowledge represented? In this paper we present an Education Ontology designed to represent ISO 37120 education indicators and the information delineated above. The ontology can be used by cities to publish their education indicators and data, using Semantic Web standards, on their Open Data portals.