The tie-up means all easyJet’s customers can now book thousands of Musement’s excursions, activities and attraction tickets in hundreds of destinations.
However, Musement excursions are only available to easyJet and easyJet holidays customers booking direct.
The airline joins several B2B partners, including booking.com, trip.com, TourScanner, Eurostar and its in-house tour operator, easyJet holidays.
Peter Ulwahn, Tui Musement chief executive, said: “This partnership underlines our position as the travel industry’s preferred partner for tours and activities.