A racing slick or slick tyre is a type of tyre that has a smooth tread used mostly in auto racing. The first production slick tyre was developed by M&H Tires in the early 1950s for use in drag racing. By eliminating any grooves cut into the tread, such tyres provide the largest possible contact patch to the road, and maximize dry traction for any given tyre dimension. Slick tyres are used on race tracks and in road racing, where acceleration, steering and braking require maximum traction from each wheel. Slick tyres are typically used on only the driven (powered) wheels in drag racing, where the only concern is maximum traction to put power to the ground, and are not used in rallying.

Slick tyres are not suitable for use on common road vehicles, which must be able to operate in all weather conditions. They are used in auto racing where competitors can choose different tyres based on the weather conditions and can often change tyres during a race.

Two stress mechanisms produce tyre grip:

Slick tyres can provide far more traction than grooved tyres on dry roads, but typically have far less traction than grooved tyres under wet conditions. Wet roads severely diminish the traction because of aquaplaning due to water trapped between the tyre contact area and the road surface. Grooved tyres are designed to remove water from the contact area through the grooves, thereby maintaining traction even in wet conditions.

Since there is no tread pattern, slick tyre tread does not deform much under load. The reduced deformation allows the tyre to be constructed of softer compounds without excessive overheating and blistering. Modern day slick tyres have now developed particular performance qualities in a specific window of temperatures, becoming sticky when accumulating enough heat, and thus give much greater adhesion to the road surface, but they also have lower treadwear ratings; i.e. they wear out much more quickly than the harder rubber tyres used for driving on the streets. It is not uncommon for drivers in some auto sports to wear out multiple sets of tyres during a single day's driving.

The first drag racing slick was developed by M&H Tires (Marvin & Harry Tires) in the early 1950s. It was the only company in the world that produced and sold original drag racing tyres.

Drag racing slicks vary in size, from slicks used on motorcycles to very wide ones used on "top fuel" dragsters. For "closed wheel" cars, often the car must be modified merely to account for the size of the slick, raising the body on the rear springs for the height of narrower slicks, or replacing the rear wheel housings with very wide "tubs" and narrowing the rear axle to allow room for the wider varieties of tyres. Open-wheel dragsters are freed from any such constraints, and can go to enormous tyre sizes. Some use very low pressures to maximize the tread contact area, producing the typical sidewall appearance which leads to their being termed "wrinkle wall" slicks. Inner tubes are typically used, to ensure that the air does not suddenly leak catastrophically as the tyre deforms under the stress of launching.

"Wrinkle Wall" slicks are now specifically designed for the special requirements of drag racing, being constructed in such a way as to allow the sidewall to be twisted by the torque applied at launch, softening the initial start and thus reducing the chances of breaking traction. As speed builds, the centrifugal force generated by the tyre's rotation "unwraps" the sidewall, returning the energy to the car's acceleration. Additionally, it causes the tyres to expand radially, increasing their diameter and effectively creating a taller gear ratio, allowing a higher top speed with the same transmission gearing.