The Circle B Bar Reserve is an area of protected lands in Polk County, Florida, United States.

[1] The park was purchased in 2000 for $7.4 million using funds provided by an environmental lands acquisition referendum approved by voters in 1994.

[2] Polk's Nature Discovery Center, completed in 2008, features interactive displays about the plants, animals, and ecosystems of the reserve.

The center serves as the focus of environmental education programs and explorations for families, school groups, teachers, adults, and other visitors.

It was purchased to help maintain the Banana Creek marsh area, home to an array of birds, such as white ibis, roseate spoonbills, sandhill cranes and bald eagles, along with other wildlife, like alligators, bobcats, snakes, gray squirrels, river otters, and wild hogs.