Abstarct: Abstract Considering the global water crisis and the challenges of energy supply, solar desalination systems are recognized as a sustainable solution for freshwater production in regions with high solar radiation. In this study, a passive and integrated solar desalination–water heating system was designed, fabricated, and experimentally evaluated. In this configuration, the heat released during the vapor condensation process is utilized to heat domestic water, thereby maximizing the use of absorbed solar energy while simultaneously producing both freshwater and hot water. A mathematical model of the system was developed baxsed on energy balance and heat transfer equations, and the results were compared with experimental data for validation. Experimental investigations were conducted to assess three filling ratios of the boiling tank (25%, 50%, and 75%), three hot water consumption patterns (no consumption, constant consumption, and variable pattern), and the effect of a reflective sheet. The results showed that a 50% filling ratio and the use of a reflective sheet led to optimal performance. The system produced, on average, about 8.5 L of freshwater and nearly 100 L of hot water per day within a temperature range of 50–60 °C. The deviation between the model predictions and experimental results was 19.8% for freshwater production and 6.5% for hot water temperature. The system operates entirely passively, without any external energy input, and can be designed with different capacities according to the required freshwater and hot water demand.