There is a lack of nationally representative data on regular e-cigarette use, as well as on the transition from experimentation to regular use. This study examines changes in these in Europe between 2014 and 2017. Data come from the 2014 (n = 27,801) and 2017 (n = 27,901) adult Special Eurobarometer for Tobacco Survey, providing nationally representative surveys of 28 EU member states. We defined regular use of e-cigarettes as daily or weekly use from a question on frequency of e-cigarette use. Among ever users of e-cigarettes we assessed socio-demographic correlates of becoming a regular user. 1.5% of the EU population were regular e-cigarette users in 2014, which had risen to 1.8% in 2017. In 2017 63 million Europeans aged 15 or older had ever used e-cigarettes (95% CI, 59.9 million–66.2 million), and 7.6 million (95% CI, 6.5million–8.9 million) were regular e-cigarette users. Among those who had ever used e-cigarettes, participants aged 15–24 years were less likely to be regular user than those aged ≥55 years (16.9% vs. 38.1%), as were never smokers compared with current and former smokers (12.8% vs. 27.0% vs. 41.3%). The proportion of adults who were regular e-cigarette users in 2017 ranged from 4.7% in the UK to 0.2% in Bulgaria. There have been slight rises in the proportion of people regularly using e-cigarettes in the EU, and this varies considerably between member states, indicating the role of the regional environment in supporting or deterring e-cigarette use.