Baillie joined Cook in October 2016 from Tui where she spent more than two decades, latterly in the role of divisional sales manager.
She will stay on for three months into the new year to help oversee a “comprehensive handover” of the role.
Kathryn Darbandi, Cook UK retail director, said: “Michelle Baillie has decided to leave Thomas Cook and I’d like to personally thank her for all that she has achieved over the last two years. Michelle remains with us for three months to allow for a comprehensive handover.”
Baillie reported to Darbandi, along with two other heads of retail for Cook’s north and west regions.
Her departure comes after Cook last month announced it would restructure its senior management team, with Anth Mooney promoted to chief of UK retail and money.
