A retractor is a surgical instrument used to separate the edges of a surgical incision/wound or to hold away certain organs and tissues (i.e. to provide tissue retraction) so that body parts underneath may be accessed during surgical operations.

The broad term retractor typically describes a simple steel tool possessing a curved, hooked, or angled blade, which is manually manipulated to help maintain a desired position of tissue during surgery. More sophisticated retractors may be clamped in place (usually to a tableside frame) or suspended at the end of a robotic arm. Retractors can also be "self-retaining" and no longer need to be held once inserted, having two or more opposing blades or hooks which are separated via spring, ratchet, worm gear or other method. The term retractor is also used to describe distinct, hand-cranked devices such as rib spreaders (also known as thoracic retractors, or distractors) with which surgeons may use to forcefully drive tissues apart to obtain exposure. Different surgery specialties can have specific kinds of retractors - e.g., for certain kinds of spinal surgery, such as Minimally Invasive Transforaminal Lumbar Interbody Fusions, some retractors are fitted both with suction and with fiberoptic lights to keep deep surgical wounds both dry and illuminated.

Surgical assistants, whether they be another surgeon, surgical residents or professionally trained procedure assistants (specifically Certified Surgical Assistants, Registered Nurse First Assistants, Physicians Assistants, or Surgical Technologists), may assist the operating surgeon in the process of retraction.