The brief covers brand strategy and UK media and influencer relations for the group's 14 UK restaurants, which include Petrus, Maze and the Savoy Grill. There are a further 16 overseas restaurants, with the group's chefs holding a total of six Michelin stars.
TCS takes over from incumbent agency Roche, which held the Gordon Ramsay account for two years.
Fiona Hemming, TCS divisional director, said: "Following a competitive tender, it is a huge privilege to be the appointed communications partner for Gordon Ramsay Group. We are very proud to be working with one of the world's best restaurant groups and feel that this new partnership represents the group's focus on strategic brand development."
The UK's 24th largest PR firm, TCS's clients are primarily in the fashion and beauty sectors, although the agency works with high-profile chef Simon Rogan and restaurant brand Roka. Other clients include drinks brands Dom Perignon and Veuve Clicquot.
Last year, Gordon Ramsay Group comms director Jo Livingston left her role to return to Freuds, whose clients include Heston Blumenthal and the Jamie Oliver Food Foundation.
