In a live interview with presenter Mark Chapman following his side's 1-0 defeat against MK Dons on February 25, Mitchell was cut off after using improper language on three occasions.
It was in response to a question concerning co-owner Maxim Demin's wife Irena's visit to the team dressing room at half-time in that match.
Mitchell attended FA headquarters for a personal hearing today morning where he admitted a charge of misconduct.
After giving an explanation, Mitchell was handed a fine of £1,500 and warned about his future conduct.
