In the present work, a solar dryer was developed to maximize solar energy. The developed solar dryer was used for drying slated tilapia fish fillets. Three fish fillets with thicknesses of 4, 8, and 12 mm were dried using the developed solar dryer at an air speed of 0.5 m/s, and the obtained data were compared with the other samples dried in open air. The obtained results showed that the drying times required to achieve a final moisture content of approximately 18.08% were 16, 18, and 21 h and 30, 33, and 36 h for the solar drying system and the sun drying system for 4, 8, and 12 mm fillet thickness, respectively. As well, average drying rates and rehydration ratio were 8.038, 7.05, 6.06 gw/gdm.h, 62.47, 67.13, and 73.27% for solar drying, compared to 4.33, 4.09, and 3.87 gw/gdm.h and 0.96, 35.85, and 42.8% for sun drying fillets of 4, 8, and 12 mm fillet thickness, respectively. It was also observed that the efficiency of the solar dryer increased from 42.35%, 44.1%, and 46.14% at average monthly solar radiation of 700, 720, and 750 W/m2 in June, July, and August, respectively. Also, the obtained results indicate that the solar dryer method is more effective in reducing the number of bacteria, yeast, and mold when compared to the sun drying method. In addition, tilapia fish fillets dried using a solar dryer received an excellent general acceptance rating with regards to color and odor.