Someone who is obsessed with doing everything rigid, proper, and by the book — even (or especially) if it interferes with doing it right.
On TV, a Control Freak is usually not the big boss; they act the way they do because they're stuck in a professional rut and they want out. Most end up as big fish in small ponds, abusing what little authority they have and hopelessly trying to impress the boss by forcing underlings to fill out all forms in triplicate with identical number-two pencils.
Every Control Freak specializes in endless stories about their past achievements, usually involving the military and usually bogus.
With a bit more power, they're the Obstructive Bureaucrat. Ten steps beyond that is The Chessmaster. Often closely related to Pride and Despotism Justifies the Means. The Neidermeyer and the Sadist Teacher are usually this.
Not all Control Freaks are self serving Glory Hounds per se, some may have perfectly kind intentions, just their egos drive them to think said kind intentions can only be set out through their way of doing things and if they are forceful enough in their ideals people will naturally see they are for the best of everyone. Several realistic mental disorders such Obsessive Compulsive Disorder can also drive otherwise pleasant people to demand things just so almost subconsciously. Most Rightly Self-Righteous characters become insufferable to others due to acting like this.
When it's parents that are involved, they're usually either a My Beloved Smother or Fantasy-Forbidding Father.
Not to be confused with the Teen Titans villain named Control Freak.