Holloway, is best known for his role as James "Sawyer" Ford in the supernatural drama "Lost."
The National Parks Project, started by Nature Valley in April 2010, supports the National Parks Conservation Association.
Organizers of the project said it will contribute up to $500,000 this year to support its work to preserve America's national parks.
"There's nothing I love more than being outside and exploring the incredible beauty of our national parks," Holloway said in a statement Thursday. "However, the parks are facing huge challenges and that's why I'm excited to be partnering with Nature Valley to help raise awareness and funds for the preservation of our national parks."
"We believe that our national parks help unite Americans with their love for nature and the outdoors -- and we often need to be reminded to slow down and take it all in," added Scott Baldwin, marketing manager for Nature Valley. "With the support of Josh Holloway, consumers and the NPCA, the National Parks Project will help ensure our national parks can be enjoyed for years to come."