Summary The recent attention in the applications of the fiber reinforced thermoplastic composite have raised some concerns because of the ability and performance of the fiber reinforced thermoplastic composite after long‐term exposures to environmental weathering (e.g., UV radiation, moisture, and oxygen). This weathering can be very destructive to the thermoplastic polymers; hence, a systematic study of the UV radiation effects on the properties of fiber‐reinforced thermoplastic composite is crucial for industrial applications. The major objective of the project was to study the correlation between thermoplastic fabrication parameters and the final properties of composites. In this study, carbon fiber (CF) reinforced polyphenylene sulfide (PPS) thermoplastic composites were manufactured using high temperature press after optimizing the parameters. Subsequently, the effects of long‐term UV exposures on the thermal and mechanical properties of CF/PPS thermoplastic composites were investigated in detail. The test results showed that the correlation between the processing parameters and the physical properties of the laminate composites were in all good agreements. The test results also revealed a significant decrease in the glass transition temperature, as well as storage modulus, and tensile strengths. Furthermore, short (200 hrs) and long (300 hrs) term UV exposures changed various thermal and mechanical properties of the thermoplastic PPS composites. This study can provide some preliminary knowledge to engineers and scientists in the field and develop new set of structural composites.