Green, who stepped down from her role at Thomas Cook last November, will be charged with developing the company’s “Internet of Things” and education offerings.
“Harriet brings to IBM a strong, proven track record as a transformative leader,” said John Kelly, senior vice president, solutions portfolio and research.
“Throughout her career, across multiple geographies and cultures, she has consistently shown a deep understanding of the needs of her customers and clients, and how to help them achieve their goals and aspirations.
“Her creativity and vision will help organizations transform themselves to take fuller advantage of emerging data and cognitive technologies.”
Green was widely credited with turning around the fortunes of Thomas Cook during her time at the company.
However, she attracted some criticism for the firm’s handling of the deaths of Christi and Bobby Shepherd, who died on holiday in Corfu in 2006.
Green was slammed in the press for taking a bonus worth around £5.6m. She pledged to give away a third of the amount to charity.