In this chapter, we present a non-orthogonal multiple access (NOMA) communication scheme to evaluate the performance of a mixed RF/FSO cooperative relaying system. The spectral efficiency of the wireless communication systems could be easily improved with the aid of NOMA technique. Simultaneous transmission of two symbols that differ in the power content that is associated with each symbol could enhance the information transfer capability of the system. Further, the relay node within this hybrid RF/FSO framework functions under the DF protocol is presented. Additionally, a direct communication link between the source and destination nodes is assumed, which boosts the system’s reliability. The radio frequency links are modeled using the Nakagami-m distribution, which effectively represents the small-scale fading in such communication channels. For the FSO links, the effects of atmospheric turbulence are described using the Malaga distribution, and a comprehensive model that accounts for a broad range of turbulence conditions is explored. The FSO link model used in this study also considers the impact of pointing errors and includes two types of optical demodulation techniques such as Intensity Modulation/Direct Detection (IM/DD) and coherent demodulation. For the proposed NOMA communication networks, we have derived the analytical expressions for both the outage probability and the ergodic capacity. The outage probability analysis for the mixed RF/FSO DF system has been extended to high SNR regime and allowing the results to be expressed in elementary functions. This analytical framework provides a deeper understanding of different radio frequency and FSO system parameters that affect the overall reliability and throughput of the system. Additionally, the numerical results have been thoroughly validated through the Monte Carlo simulations that confirm the accuracy of the analytical expressions and offer insights into the practical performance of the proposed mixed RF/FSO NOMA system under various operating conditions. This comprehensive analysis underscores the potential of NOMA communication networks in improving the efficiency and capacity of the hybrid communication systems. By addressing the specific challenges associated with both radio frequency and FSO links, this chapter contributes to the development of robust and high-performance wireless communication technologies.