The purpose of the study was to ascertain the effects of innovation types and environmental antecedents on performance outcomes of Metropolitan, Municipal and District Assemblies in Ashanti region, Ghana. Specifically, the study measures the mediating effects of environmental antecedents on the performance outcomes of the MMDAs. A total of 280 responses received from interested workers of the MMDAs were used for the study. As a result of the Covid-19 and its related restrictions, the questionnaire was developed using Google forms. Data were collected through social media and the responses received were screened and used for the analysis. The questionnaire was based on measurement scales for the key variables (innovation types, environmental antecedent, performance outcomes) understudy. SPSS and Sobel Test were used to estimate the mediation effect. The study results revealed that there is a significant but negative relationship between innovation types and performance outcomes at the MMDAs. Similarly, a significant and positive relationship was found between environmental antecedent and performance outcomes of the MMDs. Again, the results showed that there is a relationship between innovation types and performance outcomes of the MMDAs. Finally, the results showed that environmental antecedents mediate the relationship between innovation types and performance outcomes of the MMDAs. Based on the findings, the study recommends that managers of the MMDAs should continue to monitor and control the various environmental (public demands, political demand, regulatory frameworks, competition) forces within the public sector in order to realize the full potential of innovation and its role in facilitating performance outcome. Also, the MMDAs should embrace the innovation types (process innovation, process innovation, governance innovation, and conceptual innovation) in order to achieve higher performance outcomes (effectiveness, efficiency, citizen involvement and participation and customer satisfaction).