Objective: The purpose of this study was to determine if there is a relationship between pain and movement kinematics during functional tasks, evaluated over time, in individuals with chronic idiopathic neck pain. Methods: Ten participants with chronic idiopathic neck pain performed 2 functional tasks (overhead reach to the right and putting on a seatbelt) while evaluated using 8 Oqus 300+ cameras. Kinematic variables included joint angles and range of motion (ROM) (°), head segment relative to neck segment (head-neck [HN]); and head/neck segment relative to upper thoracic segment (head/neck-trunk), velocity (m/s), and time (% of movement phase). Pain was quantified using a 100-mm visual analog scale. Linear mixed effects regression models were used to analyze associations between pain and kinematic variables adjusting for treatment group. Results: For overhead reach, higher pain was associated with less HN peak rotation at baseline (β = -0.33; 95% CI -0.52 to -0.14, P = .003) and less HN total rotation ROM at 6 months (β = -0.19; 95% CI -0.38 to -0.003, P = .048). For the seatbelt task, higher pain was associated with less HN peak rotation (β = -0.52; 95% CI -0.74 to -0.30 to -0.74, P < .001) and less HN total rotation ROM at baseline (β = -0.32; 95% CI -0.53 to -0.10, P = .006). No other movement variables demonstrated meaningful relationships with pain for the reach or seatbelt tasks. Conclusion: Higher pain is associated with less HN peak and total rotation during functional reaching tasks requiring head rotation. Recognizing altered functional kinematics in individuals with chronic neck pain may assist patient management.