Darcey Tempest, of The Burrows, Birstall, applied for the trip through her school, which organised the life-changing experience.
Having been selected, the Wakefield Girls’ High School pupil is now looking forward to the journey in July 2015.
In the meantime, she must raise £3,500 to fund her expedition to South America.
Her proud father, Wayne, said: “There are only so many places available so I am delighted she got chosen.
“She realises how big a benefit having something like this on her CV will be.”
The 16-year-old will take part in projects helping less fortunate communities.
She will also be working on a program dedicated to the conservation of turtles.
Wayne said his daughter really deserves the trip after being diagnosed with a blood disorder last year.
He said: “She was diagnosed with idiopathic thrombocytopenic purpura (ITP).