Aerial launch and/or recovery for unmanned aircraft, and associated systems and methods. A representative method for operating an unmanned aerial vehicle (UAV) system includes directing a first, multi-rotor carrier aircraft to carry a second, carried aircraft aloft, and release the second aircraft for flight, while powering the first aircraft with an on-board battery. The method can further include directing the first aircraft to position a capture line in a flight path of the second aircraft to capture the second aircraft.