The two UK brands, which are part of Tui UK & Ireland, will introduce St Lucia and Cayo St Maria, an island just off the coast of Cuba, from next May.
Tui will use the 787 Dreamliner to fly to the destinations.
Closer to home, Thomson customers will be able to travel to Olbia in Sardinia, staying in two newly-renovated hotels.
Mark Hall, director of product for Thomson and First Choice, said: “Our focus remains on the growth of our long-haul using our fantastic 787 Dreamliner and I think St Lucia will be a particular highlight for summer 2017 with its luxurious hotels, palm-fringed beaches and lush rainforest.
"Equally we’re pleased to introduce the stunning island of Cayo St Maria in Cuba and, closer to home, the beautiful beaches of the Olbia region in Sardinia to our line up for next year."
