© 2021 Taylor & Francis Group, LLC.Objective: To investigate biomechanics, muscle performance, and disability of the craniocervical region in temporomandibular disorder (TMD) patients and compare them with controls. Methods: Craniocervical posture was evaluated using lateral photography and radiography. Range of motion, muscle performance, disability, and TMD severity were assessed using an inclinometer, Functional Strength Testing of Cervical Spine, Neck Disability Index, and Fonseca Anamnestic Index, respectively. Results: Compared to the control group, the TMD group demonstrated higher cervical flexion angle (p=0.005) and neck disability (p<0.001) as well as lower cervical extension (p=0.040), right cervical rotation (p=0.005), left cervical rotation (p<0.001), and tragus-C7-horizontal (p=0.048) angles, and reduced muscle performances (p≤0.001). Most patients had higher than normal craniocervical angle (p<0.001). Muscle performance in each cervical motion (p<0.005) and disability (p<0.001) were associated with TMD severity in the TMD group. Conclusion: Biomechanics, muscle performance, and disability of craniocervical region were altered in the TMD group.