Some demonstrative embodiments include apparatuses, systems and/or methods of geofencing. For example, an apparatus may include a geofencing detector to trigger a first location scan for a first location fix of a mobile device; and a location calculator to dynamically update an activity-based location area of the mobile device relative to the first location fix, based on a plurality of detected activity states of a user of the mobile device, the plurality of detected activity states corresponding to a plurality of detection points subsequent to the first location scan, wherein the geofencing detector is to trigger a second location scan for a second location fix of the mobile device, based on the activity-based location area and a geofencing boundary.