Falls continue to be a major safety and health concern for older adults. Researchers reported that increased gait variability was associated with increased fall risks. In the present study, we proposed a novel wearable soft robotic intervention and examined its effects on improving gait variability in older adults. The robotic system used customized pneumatic artificial muscles (PAMs) to provide assistive torque for ankle dorsiflexion during walking. Twelve older adults with low fall risks and twelve with medium-high fall risks participated in an experiment. The participants were asked to walk on a treadmill under no soft robotic intervention, inactive soft robotic intervention, and active soft robotic intervention, and their gait variability during treadmill walking was measured. The results showed that the proposed soft robotic intervention could reduce step length variability for elderly people with medium-high fall risks. These findings provide supporting evidence that the proposed soft robotic intervention could potentially serve as an effective solution to fall prevention for older adults.