The restaurant was previously represented by London-based lifestyle agency, Kitchen Communications, until April.
After a competitive pitch process, Stir PR has been appointed on a one-year retainer. It is not known how many agencies it was up against.
The account move comes after the opening of Morgans Hotel Group’s new Mondrian hotel on London’s Southbank. The new hotel, which opened in September, is located between the OXO Tower and Blackfriars Bridge and houses two restaurants and two bars.
Kerri McGuinness, marketing and communications manager for the OXO Tower restaurant, bar and brasserie, said: "With so many exciting new ventures on the horizon, we needed an agency that had a positive energy, creative vision and the contacts to hit the ground running; Stir had all three and we look forward to working with it."