Power take-off control system and method.

A PTO control system and method for engaging a PTO clutch (18) of a vehicle (12) or work machine such as, but not limited to, an agricultural tractor, that can effectively utilize both engine speed and PTO output speed values for determining a predicted and/or actual PTO load and other variable conditions which can effect engagement, and which can responsively calibrate the system for engagement under the load and other conditions and adaptively control applied acceleration and torque during the engagement.