Charles Christopher Frost (November 11, 1805 – March 16, 1880) was an American mycologist.

His parents were shoemaker James Frost and Elizabeth Stewart, daughter of an officer in the American Revolution.

When he was fifteen, Frost left school after being hit with a ruler by a teacher, and assisted his father with his business.

Although Frost had developed a prior interest in the natural sciences, his interest in botany grew after meeting with physician Willard Parker, who recommended Frost undertake botanical walks to alleviate the symptoms of his dyspepsia.

Frost started studying the mosses and lichens he encountered on these walks.