An airbag assembly for leg flail protection and associated systems and methods are described herein. An airbag system configured in accordance with an embodiment of the present technology can include, for example, a housing having a cavity and an opening in communication with the cavity, an airbag stowed within the cavity, and an inflator operably coupled to the airbag. The airbag can be configured to deploy through the opening of the housing during a crash or other significant dynamic event. The airbag can deploy outwardly from the side-facing seat to reduce occupant leg rotation during the crash or other significant dynamic event. The airbag can be pushed out of the housing before it is fully inflated. The airbag can be stowed and include folded first and second opposing side portions such that when the airbag is deployed, the portion nearest the occupant unfurls toward the occupant prior to the other portion farthest from the occupant unfurling in a direction away from the occupant.