Muskmelon or cantaloupe (Cucumis melo L.) juice receives consumer preference throughout the world due to its sweet taste and flavour. The present research was aimed at investigating the impact of rotary vacuum evaporator-based conventional heating (CH) and microwave heating (MH) on the quality characteristics, i.e., pH, TSS (°Brix), TA (%), conductivity (ms), water evaporation rate (g/min), colour index, and total phenolic content (TPC mg GAE/mL) of Cucumis melo juice. The processing conditions for CH were temperature (50 °C, 70 °C, and 90 °C) and time (1 min, 1.5 min, and 2 min), whereas for MH, the processing conditions were microwave power (450 W, 600 W, and 900 W) and time (1 min, 1.5 min, and 2 min). The results illustrated that CH and MH affected the quality characteristics of Cucumis melo juice significantly. Among all the treatments, the water evaporation rate and TPC were the highest at 900 W for 2 min. Additionally, TCD among all the treatments was found to be minimum (0.56) when Cucumis melo juice was treated at 450 W for 1.5 min. Thus, MH treatment can be considered as an alternative to CH treatment. Overall, the present research provides insight into the treatment process of Cucumis melo juice, which can further enhance its quality characteristics and impact the global market.