Ms Swann has been named as chief executive of SSP, which runs restaurants, bars, cafes and convenience stores at airports, train stations and shopping centres for brands including Starbucks, Burger King, M&S Simply Food and Upper Crust.
Her appointment to the private equity-owned group comes after 10 years running the high street retailer and follows speculation linking her with top roles at retail giants Next, Sainsbury's and Marks & Spencer.
Ms Swann, who is widely credited with turning around WH Smith by focusing it on travel locations, announced her decision to quit last October and left the retailer last week. She takes up the new role on September 4.
Ms Swann said: "I am delighted to be joining SSP and look forward to working with the team as we continue to grow the business and deliver for our customers."
She succeeds Andrew Lynch at the helm of SSP, who is standing down after nine years.
SSP chairman Vagn Soerensen said: "SSP will benefit from Kate's vast retail experience from WH Smith in accelerating growth and working with business partners, while continuously improving the customer experience."
It employs about 30,000 staff including about 10,000 in the UK and Ireland, where it has more than 700 units at Glasgow Central, Birmingham New Street, Waterloo and London Euston stations, as well as Manchester, Newcastle and Dublin airports.
The group had underlying earnings of £139 million in 2012 on sales of £1.7 billion.