Earl, who has worked with Zeno group for nearly seven years and previously set up and ran the agency Speed Communications for 14 years, joins APCO on 1 July.
"I am delighted to welcome Steve to lead APCO’s London office during such a critical period for the UK, Europe and the global marketplace, especially given the projected instability and uncertainty in a post-Brexit world," APCO Europe president Claire Boussagol said.
Earl set up Zeno’s London operations in 2012 and has overseen client delivery and business development across multiple European offices, playing a leading role in the acquisition of 3 Monkeys Communications in 2016.
He has counselled clients on corporate communications, brand engagement and crisis management and is a regular in the PRWeek Power Book.
Prior to his tenure at Zeno Group, Earl founded integrated communications firm Rainier PR with Steve Waddington (now Speed Communications) and ran it as MD for 14 years.
He began his career as a reporter, working at the Shropshire Star, and has previously worked as an account director at Weber Group (now Weber Shandwick).
"I am thrilled to join APCO and lead a hugely talented team of professionals in London. I look forward to working together to accelerate UK growth," Earl said.
"We want to unleash the full force of our worldwide network to drive greater value for global, regional and local clients across a broader array of services.
"It’s an irresistible challenge for me to get my teeth into and I couldn’t think of a better team to work with to accomplish this goal."
Zeno Group CEO Barby Siegel said: "Steve has been a driving force in helping Zeno to establish and grow our presence in Europe. We thank him for all that he has done and wish him the very best for the future.
When asked whether Zeno Group had lined up Earl's replacement, Siegel added: "We don’t discuss specific hiring plans but we have a strong senior team in place and we will continue to deepen our capabilities in the UK and across Europe as our business continues to expand."
This year is the 35th anniversary of APCO Worldwide, which is ranked 57th in this year’s PRWeek Top 150 Consultancies report, with annual revenues of £6.14 million and 61 staff.