The cerebellum undergoes neuroplastic changes in response to motor learning. Healthy human individuals demonstrate reduced cerebellar inhibition (CBI) following motor learning. Alterations in neck sensory input due to muscular fatigue are known to impact upper limb sensorimotor processing, suggesting that neck fatigue may also impact cerebellum to motor cortex (M1) pathways in response to motor learning. Therefore, this study aimed to determine whether cervical extensor muscle (CEM) fatigue alters CBI in response to motor learning. We examined sixteen participants (8 CEM fatigue and 8 CEM control). A double cone TMS coil stimulated the ipsilateral cerebellar cortex 5 ms prior to application of contralateral test stimuli of the M1 to the right first dorsal interosseous muscle. Cerebellar-MI activity curves were established pre- and post- motor skill acquisition (consisting of tracing sinusoidal-pattern waves with the index finger), and following either the CEM fatigue or control intervention. The control group showed greater cerebellar disinhibition than the fatigue group following motor skill acquisition (p<0.006), while the fatigue group showed similar levels of CBI pre- and post-motor skill acquisition. Both groups improved in accuracy following acquisition (p= 0.012), and retention (p= 0.007), but the control group improved significantly more (17% at acquisition and 22% at retention) vs lower (6% and 9%) improvements for the fatigue group. Lessened cerebellar disinhibition in the CEM fatigue vs. control group, coupled with diminished motor learning, suggests that CEM fatigue affects the cerebellar-MI interaction, influencing the cerebellum's ability to adjust motor output to acquire and learn a novel motor task.