maverick

A maverick is someone who refuses to follow the conventional path, especially in politics or business.

The word suggests independence and nonconformity—a willingness to break from the group: She was a maverick who voted against her own party.

Originally, a maverick was an unbranded calf separated from its mother, available for anyone to claim.

The term still appears in ranching contexts but is far more common as a metaphor for someone who goes their own way. (Capitalized Maverick is a surname or brand name.)