The vast developments in the electronic industry over the past few decades have provided smaller and lighter electrical components that spurred advances in dexterous upper extremity prostheses. Prosthetic companies have commercialized anthropomorphic artificial hands including over 10 different grasp patterns and auto grasp features to prevent objects slipping. However, wrist function remains inadequate. This forces prosthetic users to compensate for lack of wrist function, causing musculoskeletal pain in the neck/upper back, shoulders, and the residual arm. Adding a multiple degree of freedom wrist to the already overweight hand prostheses forces research in alternative actuation methods. Considering these issues and the fact that past studies have shown pneumatic actuation to be a promising lightweight option to actuate upper extremity prostheses, the goal of this research is to develop a functional lightweight pneumatically powered two-degree-of-freedom wrist prosthesis. The developed prototype is designed to actively move the wrist in a certain position where it will passively lock in place in order to be able to perform the desired task. With a weight of 95.4 grams and a with a circumference similar to the average human wrist, the final prototype enables enough output torque to employ a 500 gram prosthetic hand over a maximum range of motion of 42°/42° for flexion/extension and 51°/52° for pro-/supination. In its current form, however, significant improvements can be made by optimization of material choice in order to reduce friction, reduce weight, and increase the amount of torque the locking mechanism can withstand. All things considered, this prototype reveals that pneumatically actuated prostheses show promise of becoming a true lightweight competitor for the current industry standard in upper extremity powered prosthetics.