ABSTRACT: The purpose of this case report was to describe the impact of the use of orthoses on the gross motor skills of a 3-year-old child with Noonan syndrome (NS). Low muscle tone and muscular weakness, which are common symptoms in children with NS, can lead to difficulty with gross motor skills that require propulsion and balance. It was hypothesized that improved biomechanical alignment of the foot and the ankle through the use of orthoses would enhance gross motor skills. The child was provided with bilateral supramalleolar orthoses (SMOs) and participated in an 8-week intervention program consisting of strengthening and balance exercise, developmental training, and practice of motor skills. SMOs are lower-limb orthoses that provide hindfoot, midfoot, and forefoot control. The SMOs that were fabricated for this child provided control from just above the ankle to the metatarsal heads. Outcome measures included the Peabody Developmental Motor Scales–2 (PDMS-2) to quantify gross motor changes, a pedograph to measure gait parameters, and parent interview. These measures were taken before, after, and at follow-up sessions both with and without orthoses. After 8 weeks of wearing orthoses during all upright weightbearing activities, the child demonstrated improved scores on all parameters of the PDMS-2, improved gait characteristics on the pedograph, and increased gait speed while wearing the orthoses. In addition, through interview, the child’s family reported satisfaction with the outcomes. The results from the parent interview indicated that the child exhibited decreased complaints of foot pain, decreased difficulty with functional motor skills, and improvements with keeping up with peers in recreational and school-based activities. Improvements were also seen in Gross Motor Quotient (GMQ) scores, step length, step width, stride length, and running speed after 8 weeks, when the child was tested without wearing orthoses, as compared with baseline. Providing external supports in the form of SMOs for a 3-year-old child with NS brought about an improvement in gross motor and mobility skills as measured by standardized testing and subjective interview. Such improvement may be related to improved biomechanical alignment provided by the SMOs and consequential motor learning when not wearing the SMOs after training. This adjunct should be considered for other children experiencing low muscle tone and difficulty with skills, especially those requiring propulsion and balance. More research is needed to determine the impact of orthotic intervention on other populations.