Smith, who was head and sales and service for Tui’s Special Holidays Group prior to joining Great Rail Journeys, will depart on August 24.
The search for her replacement at Great Rail Journeys is underway.
Alex Roberts, group sales and marketing director, said: “Sharon has been key to the growth of Great Rail Journeys over the last three years and has made a big impact in developing our trade sales.
“Sharon will be very much missed within the business – and no doubt the agents that support us - but we wish her well in her future ventures.”
Since joining the operator in 2014 Smith has headed up the group escorted touring call centre, tailor-made FIT call centre, UK and Ireland travel trade partnerships as well managing the national business development team.
Roberts added: “A succession plan for Sharon is well underway and an announcement will be made in the near future”.