Truncated flap support fairings with active flow control system for aircraft and related methods are disclosed herein. An example aircraft includes a wing having a fixed wing portion, a flap moveably coupled to the fixed wing portion, a flap support fairing coupled to a bottom of the flap, the flap support fairing having an aft end, and an active flow control system including a nozzle. The nozzle is to eject high velocity air in a streamwise direction from the aft end of the flap support fairing.