The company said in a statement that it would build its first new manufacturing plant in almost 40 years at Ulverston in Cumbria and invest more in its two sites at Montrose and Irvine in Scotland.
GSK's decision followed confirmation by the Government in the Budget on Wednesday that it will reduce the level of corporation tax applied to income from patents - a move known as a patent box.
Sir Andrew Witty, the GSK chief executive, said: “The introduction of the patent box has transformed the way in which we view the UK as a location for new investments, ensuring that the medicines of the future will not only be discovered, but can also continue to be made here in Britain."
He said investment represented one of the largest commitments to the UK life-sciences sector in recent years and will create up to 1,000 new jobs over the lifetime of the projects.
GSK is also actively considering other investments in manufacturing in the country.