This paper examines the role of social media and citizen engagement in empowering public administration for citizen-centric smart city development. It focuses on the Smart Cities Marketplace, an EU initiative providing a collaborative platform. The study evaluates citizen engagement on Twitter, analysing posts from the Smart Cities Marketplace page. Objectives include assessing the representation of smart city dimensions: Smart Economy, Smart Mobility, Smart Environment, Smart People, Smart Living, and Smart Governance, and comparing engagement levels between posts with and without related keywords. Through quantitative and qualitative analyses, the study addresses citizen engagement and representation of smart city dimensions. The findings highlight the importance of innovative and tailored approaches to leverage social media as a catalyst for smart city development. Social media is pivotal in promoting collective accountability and shaping sustainable urban development, leading to adaptable, resilient environments that improve urban liveability and life quality.