| Carry | An illegal shot, on which the ball is held and/or carried on the racket, rather than being struck. Also used as a verb. |
| Center court | The main court at a tennis arena, where the championship and other major matches are played. |
| Center line judge | An official who is responsible for watching the center service line to determine whether a serve has entered the service court. |
| Center mark | A line, 2 inches wide and 14 inches long, that marks the midpoint of the baseline. |
| Center service line | A line, extending from the net to the midpoint of the service line, which marks the boundary for both service courts. |
| Chair | The umpire's seat and, by extension, the umpire, as in "The chair ruled that the shot was out." |
| Changeover | A 90-second period after every odd-numbered game in a set, when players change sides. |
| Chip | A soft shot, hit with backspin, that just drops over the net; as a verb, to hit such a shot. It's similar to the drop shot, but is more commonly used against an opponent who is at the net, forcing a difficult volley. |
| Chop | A shot hit with a sharp, downward chopping motion, resulting in a great deal of backspin; as a verb, to hit such a shot. |
| Clean winner | A shot that cannot be reached by the opponent. |
| Closed grip | A grip in which the racket face is tilted downward, toward the court. |
| Closed racket | A racket held with a closed grip. |
| Court | The tennis court is 78 feet long and 27 feet wide for singles, 36 feet wide for doubles. It is divided across the middle by the net. Service lines are marked 21 feet from each side of the net and parallel to it. The area bounded by the singles sidelines and the service line is divided into two equal parts, the service courts, by the center service line, which is halfway between the sidelines and parallel to them. |
| Cross-court | Descriptive of a shot that is hit from one side of the court to the other, as well as over the net. For example, the player hits from the right-hand side of the back court to the right-hand side of the opponent's back court. |
| Cut | To hit the ball with a short, downward slicing motion, often drawing the racket strings across it to give some sideways spin in addition to backspin. |