In his new role, Cooper will be responsible for leading Millward Brown Optimor's practice in the UK and Europe.
Cooper has over 20 years' experience in corporate strategy and business planning, distribution strategies, market sizing and brand positioning.
Before joining Optimor, he ran his own consultancy where he worked internationally for clients in the airline, telecoms, retail and drinks industries.
Prior to that, he was managing director of the Added Value Company's London office and has also held brand management positions with British Airways and Unilever.
Joanna Seddon, EVP, who heads up Millward Brown Optimor globally, said: "In the current economic climate, making the most of your marketing investment is vital.
"We know from our research that the brands which mange this carefully, will be well positioned for when the economy improves.
"The experience that Nick has gained working with some of the biggest brands in the world means that he will be a huge asset to our European team and to the clients that we work with."
Cooper is a board member of the Association of Convenience Stores, the lobbying body for the £25bn convenience sector in the UK, holds non-executive directorships at a legal aid law firm and a multi-award winning convenience store retailer, and is a frequent speaker and commentator on retail issues.