Tobacco product advertising has been shown to reach youth and promote initiation. This study assessed trends in e-cigarette advertising expenditures in the USA during 2014-2018, overall and by manufacturer and media type.Data came from Kantar Media, which provides information on US advertising expenditures, including for e-cigarettes. Advertising expenditures were estimated as the dollar amount spent by e-cigarette companies to purchase advertising space in print, television, Internet, radio and outdoors. Dollar amounts were adjusted to 2017 dollars. Trends in e-cigarette advertising expenditures during 2014-2018 were analysed using Joinpoint regression overall, by media type, and by manufacturers based on 2017-2018 national sales.Total e-cigarette advertising expenditures in print, radio, television, Internet and outdoors decreased substantially from US$133 million in 2014 to US$48 million in 2017, followed by an increase to US$110 million in 2018. By media type, expenditures were highest for print advertising, irrespective of year. By manufacturer, Altria had the highest e-cigarette advertising expenditures, totalling over US$134 million during 2014-2018. Imperial Tobacco had the second highest, totalling over US$85 million during 2014-2018, while JUUL Labs had the highest single-year expenditures, spending over US$73 million in 2018 alone.E-cigarette advertising expenditures have been volatile in the USA, with declines in traditional advertising venues during 2014-2017 that may reflect a shift towards social media. However, an increase occurred in 2018 that is likely reflective of advertising by newer manufacturers. Continued monitoring of e-cigarette advertising is important to inform tobacco control strategies.