GlaxoSmithKline (GSK) is a pharmaceutical company with its headquarter in London, UK. It is the fourth largest pharmaceutical company in the world and was founded in 2000 by the merger of GlaxoWellcome plc. and SmithKline Beecham. GSK employs 97,000 people of which 12,500 work in research and development.

GSK has a portfolio of products for disease areas including asthma, cancer, infections, diabetes, and digestive conditions. The products are sold in 70 countries worldwide but the biggest single market are the United States with almost 50% of GSKs revenues.

In 2012 GlaxoSmithKline plead guilty to criminal charges of health care fraud and was fined a record 3 billion US dollars.