Singh starts in his newly created role today (3 September) and is tasked with optimising GSK's global media strategy, planning and buying for its global consumer healthcare and North American pharmaceutical businesses.
Singh will report directly to Jim Martin, vice-president, procurement, global consumer healthcare and North American pharmaceuticals.
GSK said the appointment would have no "immediate" implications for its media agency roster, as Singh is new to the company, adding that he would "want time to take a view on the best way to achieve his goals".
GSK's £60m UK media planning and buying account is handled by MediaCom, which lost some European markets to Starcom MediaVest Group in a 2010 review. Later that year, MediaCom lost the US account to PHD.
Singh joins from Procter & Gamble (P&G), where he was most recently vice-president of media, Asia and China. He managed the media planning operations for the global FMCG company in China, Japan, India and Australia.
Prior to this, Singh held a variety of senior roles at P&G across media planning, line marketing, sales, consumer research, forecasting and analytics.
The company is seeking to focus its portfolio on fewer global brands and capitalise on the demand for over-the-counter "wellness products".
Its portfolio includes Lucozade, Sensodyne, Beechams and Ribena.
Martin said: "GSK is on a very exciting journey to grow a diversified global business, deliver products of value and simplify our business model.
"Our new approach to media planning, buying and strategy will support that. We need to communicate to customers and consumers that GSK's science sets our brands and product quality above the competition. We need the highest-quality talent to help us do that and I'm delighted someone with Sam's track record and leadership qualities is joining the team."Follow @loullamae_es