<p>In the USA, a significant number of mayors utilize social media, especially X (formerly known as Twitter), to disseminate municipal information and foster relationships with their constituents. However, there is a scarcity of research examining the patterns of these expressions and their effects on citizen engagement. This study explores the patterns of mayors’ X disclosures, their correlation with individual characteristics of mayors, and levels of citizen engagement. The findings suggest that longer-serving mayors typically employ richer linguistic expressions and a more formal tone. Male mayors lean toward authentic expressions and spatial references, while female counterparts spotlight human rights and social issues. Political affiliations also influence their X content, with Democratic mayors emphasizing positive sentiments and social processes, while their Republican peers focus on societal well-being. Additionally, the governing system under which a mayor operates, whether mayor–council or council–manager, dictates their communication style and themes. Notably, emotional expressions tend to bolster citizen engagement, whereas informal language can deter it. A deeper analysis contrasting the pre- and post-COVID-19 eras is also undertaken. This research contributes to the government information literature by analyzing mayors’ X expressions and offers insights into leveraging online communication to enhance citizen engagement.</p>