Abstract Background Physical activity/inactivity is impacted by a plethora of intertwined factors. There are a limited number of studies on physical activity/inactivity that provide a European cross-country perspective. This study aims to present the prevalence and correlates of physical activity in adults across the 28 European Union (EU) member states. Methods This is a secondary dataset analysis of the Special Eurobarometer 472 data on physical activity. The cross-sectional survey was conducted during December 2–11 in 2017 across 28 European countries. The data consisted of ∼1000 respondents aged ≧15 years per country. The current analysis was restricted to adults aged 18–64 years (n = 19 645). Results More than one in three (36.2%, 95% CI: 35.1–37.3) adults in the EU were physically inactive, with substantial cross-country differences noted. Women were less likely than men to be adequately or highly physically active (aOR: 0.86, 95% CI: 0.78–0.95). Similarly, adults at the age of 40–54 (aOR: 0.65, 95% CI: 0.52–0.81) and 55–64 (aOR: 0.61, 95% CI: 0.49–0.77) were less likely to have moderate or high levels of physical activity in comparison with those 18–24 years of age. Finally, high SES was positively associated with physical activity (aOR: 1.4, 95% CI: 1.16–1.69). Conclusions A notable percentage of adults in Europe are physically inactive. Further research is needed to elucidate the factors behind the cross-country differences and identify potential policy actions that may support adopting a physically active lifestyle and decrease the inequalities related to physical activity across Europe.