Digital twins play a key role in the digital transformation of smart cities. Understanding the distinct concepts as well as the comprehensiveness and maturity of digital twins is, however, not yet fully researched. In this study, we identified, analyzed and compared five maturity models for digital twins in smart cities, based on a systematic literature analysis following Carrera-Rivera et al. approach [1]. The criteria for comparison comprise maturity levels, capabilities, technologies used and data used at each maturity level. We reflect on these identified components of digital twin maturity models. Our findings indicate that researchers have found some consensus about digital twin maturity levels and capabilities that emerged in recent years, but only one model recognizes the “full lifecycle” capability. However, further research is needed to develop a comprehensive maturity model for digital twins in smart cities that guides researchers and practitioners in the exploitation of the full scope of digital twins. The research at hand provides the foundations for future research to develop a more detailed and sophisticated maturity model for digital twins in smart cities.