Jeremy Smith has been appointed climate specialist, Elke Dens director of global programmes and Rebecca Armstrong, Kelly Galaski and Alicia Fajardo as sustainable tourism specialists.
The new additions come as the charity aims to increase focus on its climate change output, following two "challenging years of rapid change and adaptation" in travel and tourism.
The charity has joined the Tourism Declares a Climate Emergency initiative and is providing ongoing support for the Glasgow declaration by working in collaboration with the UN’s World Tourism Organisation (UNWTO).
It is also working with several US destinations where the pandemic has brought new challenges and impacts, such as California, Port Aransas and Vail.
Jeremy Sampson, Travel Foundation chief executive, said it is "an exciting moment" for the charity.
"We’re in a position to share and scale knowledge about how to better understand and improve the impacts of tourism and address key issues such as climate change and equity," he added.
"Our new projects and initiatives are bold and progressive and will give us more great examples that can inspire change globally."
The Travel Foundation now has team members now based in eight countries, reflecting the "global nature" of the organisation’s work.