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The heat pump operated single-stage humidification-dehumidification desalination system, configured with a subcooler and a heat regenerator, has been proven highly effective in improving both freshwater productivity and energy efficiency. To investigate the potential benefits of increasing the number of humidification stages, this paper presents a heat pump operated two-stage humidification-dehumidification desalination system by adding a pre-humidifier. Subcooler and condenser of the heat pump are used as the heat sources of the main humidifier and the pre-humidifier, respectively. Through parametric studies, a comparative analysis is conducted on the thermodynamic and economic performances of both the heat pump operated single-stage system and two-stage system at various operating conditions. The results show that such system modification can greatly improve system performances. Compared to the single-stage system, the maximum freshwater productivity of the two-stage system is 42.89 kg/h, increased by 19.77 %; the peak gain output ratio is 7.93, up by 9.53 %; and the lowest specific electricity consumption is 79.34 kWh/m3, reduced by 15.15 %. Furthermore, the freshwater production cost for the two-stage system, ranging from 7.78 to 13.33 $/m3, is also superior that of the single-stage system, further demonstrating its substantial value in practical product development and market promotion. • A heat pump operated two-stage humidification-dehumidification system is proposed. • Performances of single and two-stage systems are compared at identical conditions. • Freshwater production costs of the two-stage system range from 7.78 to 13.33 $/m3. • The two-stage system is significantly more efficient than the single-stage system. [ABSTRACT FROM AUTHOR]