Filler will be responsible for running the UK's branded video content distribution business, goviral, and ad network Advertising.com.
He will start in his new role on 3 September and will report directly to René Rechtman.
Adam Boast previously held the UK MD position for goviral, with some responsibility for Advertising.com. According to AOL, he decided to leave the business earlier this year.
With more than 18 years' experience in digital advertising and sales, Filler will focus on growing the Advertising.com group's presence in the UK, capitalising on its leading reputation for partnering premium publishers, advertisers and agencies to maximize the value of online brands.
Prior to joining the Advertising.com group, Filler held the position of managing director at media and technology network Collective, and before that, was commercial director at Unruly Media and before that, he was at Videojug.
He built his career in digital at The Guardian, where he held the role of advertising and sponsorship manager.
Filler said: "As the digital world continues to evolve at a rapid pace, I was looking for a company that had the foresight and ability to deliver cutting-edge campaigns that respond to changing consumer behaviours.
"The role at the Advertising.com Group offers me the chance to lead a highly talented team with fantastic digital products that push the boundaries in video and display advertising, creating innovative and effective solutions for brands."
René Rechtman, senior vice-president of Advertising.com group international, said: "Steve’s commercial acumen, unrivalled knowledge of digital advertising and network of industry contacts will be hugely beneficial to the Advertising.com Group.
"We have ambitious plans for goviral and Advertising.com and some exciting products in the pipeline. We're excited to have Steve on board to help take the UK business to the next level.
In addition, Adtech, an ad serving company within the Advertising.com group, has hired Suhela Gremmel as its new UK managing director.Follow @nickbatten2