Grey London has picked up 64 new accounts since Davis joined the WPP-owned agency as new business and marketing director in 2009. She was promoted to chief marketing officer in October 2013.
She has also worked at Rainey Kelly Campbell Roalfe/Y&R, Burkitt DDB, Leo Burnett and TBWA.
Davis will report into Cheil’s chief operating officer, Matt Pye, and will be responsible for driving business growth across Europe, with a specific focus on the UK market.
Pye said: "Cat’s new business record at Grey speaks for itself. She’s a phenomenal appointment and follows hot on the heels of Lotta Malm-Hallqvist [joining] as global growth officer.
"This underlines Cheil’s ambition to secure rapid growth with high-quality clients."
Hallqvist joined in January with a remit to strengthen the agency’s global position. Shortly after her appointment Cheil hired Malcolm Poynton, the former European creative officer at SapientNitro, as its first global chief creative officer.
Davis featured on the IPA and Campaign’s shortlist for the Women of Tomorrow awards last year. She was one of 24 women featured from across the advertising, media and communications industry.
She said: "The opportunity to join Cheil – an agency with the ambition and passion to become a force to be reckoned with locally, regionally and globally, is one that was too great to resist.
"I’ve had an incredible six years at Grey. It’s been fantastic being a senior part of their turnaround story and I’m now relishing a new challenge."
Grey will now promote Sarah Jenkins, the head of account management, to be its new chief marketing officer.
Jenkins, previously of Rainey Kelly and TBWA, has led major pitches for the agency, as well as leading on accounts for Lucozade and the British Heart Foundation.
She said: "Change is coming, not just to Grey London, but to the whole industry, so it's a very exciting time to be sitting in a new business role. The fact I get to be doing this job at an agency that is on its A-game... suddenly it all gets very special."