The Breakaway Leg Sling is provided for use with a walker or crutches and suspends a single leg in a below-the-knee cast, shoe, or bandaged foot in a rearward, elevated position and assists the patient with weight avoidance on the suspended leg. The apparatus is prepared for use from a safe sitting position, and the leg is placed into its suspended position during the natural motion of standing. If needed, the apparatus includes a breakaway safety fastener that disengages at an effective, pre-determined force using the muscles of the suspended leg thereby providing the patient with immediate use of the suspended leg to regain balance and prevent a potential fall. If disengaged, the safety fastener is easily restored to operational use. The Breakaway Leg Sling is comprised of a torso harness device, a detachable foot cradle device, a load strap used to engage the torso harness to the foot cradle device, and the breakaway safety fastener incorporated into the length of the load strap. The foot cradle device may be left on the foot for extended periods of time without hampering the patient's comfort thereby leaving the foot cradle anchor in a ready-to-connect position. If desired, the foot cradle device may be removed for bathing or other purposes, and the foot cradle device will retain its custom size thus saving the patient time and effort when replacing the foot cradle device on the foot or cast.