King starts in early December, reporting to Iris global CEO Ian Millner.
He will be based in Shanghai, responsible for Iris clients in the region, particularly Sony Ericsson, an account serviced out of the Iris Beijing office launched earlier this year.
King's appointment follows last month's announcement that Josh Thomson will take up the role of regional CEO for APAC, which will see him responsible for all Asia Pacific markets outside of China.
Iris board director Chris Martell, who has been running the Sony Ericsson business in Asia for the past 18 months since joining from TBWA/Tequila, will relocate from the Singapore office to Beijing to lead the business across China.
The group plans to expand in Asia through organic growth, partnerships and acquisitions. The agency has identified China, Indonesia and India as key markets for expansion.
"The opportunity in China is huge and as we focus on driving our ambitious expansion plans in the region and other emerging markets, we look to attract the best in talent," Millner said.
"Bringing on board someone of David's calibre, who has a proven track record and vast experience of the region, is fundamental to helping us grow the iris offering in what is fast becoming one of the most important markets for both us and our clients' business."
King joined Rapp's Shanghai office as managing director in January 2007, following the sale of Tarantula China - the company he co-founded - to the Publicis Groupe network.
He helped grow Rapp China from a start-up to a well-established agency of 37 people with clients such as IHG, Friesland Campina, Johnnie Walker, HP and Virgin Atlantic.
In 1998 King set up Tarantula in 1998 with five former colleagues, going on to open anoffice in Moscow to service British American Tobacco and launched a major cigarette brand in Russia. King moved to Shanghai in 2002.
He started his career in retail management, then as a brand manager for Visionhire - a UK consumer electronics retailer - before moving agency side to work for Haygarth and CSP.