The Toyota K CVT transmission is a series of continuously variable transmissions (CVT) found in many Toyota and Lexus automobiles. The transmissions are manufactured for the company by Aisin, an automotive parts manufacturer that is part of the Toyota Group of companies. A CVT is a type of automatic transmission that can change seamlessly through a continuous range of gear ratios. This contrasts with other transmissions that provide a limited number of gear ratios in fixed steps. The K series uses two pulleys connected by a belt.

A continuously variable transmission (CVT) is an automated transmission that can change through a continuous range of gear ratios. This contrasts with other transmissions that provide a limited number of gear ratios in fixed steps. The flexibility of a CVT with suitable control may allow the engine to operate at a constant angular velocity while the vehicle moves at varying speeds.