Jones will be supported by Daniella Bertolone, who has been promoted to head of operations and client services.
He will be responsible for driving the growth and overseeing the strategic direction of the agency, whilst delivering "impactful, creative campaigns for Mischief’s clients". He will report to Engine Communications and MHP CEO Alex Bigg.
Jones was the lead on some of Mischief’s biggest new business pitches – for clients including Coca-Cola, Unilever, Asda and Henley Business School.
Bertolone, who has been a partner at the agency for the past two years, will work with Jones across the business to support and grow Mischief’s roster of clients, which includes ODEON, LEGO, Honda, TUI and Vodafone.
"I’m excited by this opportunity to propel Mischief into a new era," Jones said. "I’m looking forward to working with Daniella and an incredibly talented management team to continue to deliver the award-winning, attention grabbing work Mischief is famous for, as well as evolving our offering to meet the ever-changing needs of our clients and the media landscape."
Bigg added: "I’m delighted with the new leadership team at Mischief. Mischief has always been a force to be reckoned with, but with Greg and Daniella now at its helm, I believe the agency is entering an exciting new chapter."
Mischief said it has had its most successful first half-year to date, with a haul of industry awards.
Last month Mischief earned industry recognition for its spoof Saynts Fyre Festival Kit launch for Southampton Football Club, which parodied the infamous Fyre Festival and has gone on to become the club’s best-ever performing campaign across its social channels.
So far in 2019, it has received more than 50 award nominations and 13 industry awards.