Retraction and aspiration devices, systems, and methods are disclosed herein. One aspect of the present technology, for example, is directed toward an apparatus for use with a catheter system configured to enable intravascular delivery of an interventional device to a treatment site in a blood vessel. The apparatus can include a housing configured to be releasably coupled to a proximal portion of the catheter system and an actuation mechanism coupled to the housing. The actuation mechanism can include a lever movably coupled to the housing, a locking portion configured to engage a portion of the catheter system, and a pressure source coupled to the housing and the actuation mechanism. Movement of the lever simultaneously activates the pressure source to generate pressure, and moves the locking portion to engage and retract at least a portion of the catheter system.