This study evaluates the viability of small modular reactors (SMRs) as a carbon-neutral energy source for various desalination configurations such as SWRO, MED, and MSF. Analyzing both a 79.4 MW e unit and a 317.6 MW e packaged configuration, we found that MED and MSF processes increase the levelized cost of electricity (LCOE) by over 40 % due to a 28 % reduction in the electricity output capacity of SMRs caused by the use of back-pressure steam turbines. Consequently, the levelized cost of water (LCOW) for MED and MSF rose by 17 % and 20 %, respectively, compared to the SMR-powered SWRO setup. Renewable energy sources with energy storage systems which could provide continuous electricity for desalination are analyzed for comparison, showed significantly higher costs, with LCOE for onshore wind and PV at 126 % and 190 % higher than SMR case. The corresponding LCOW was 57 % and 85.6 % higher than the SMR-powered SWRO configuration. These findings highlight SMR's superior economic feasibility and their potential in decarbonizing desalination, alongside their future role in reducing hydrogen production costs through water electrolysis. Unlike renewables, SMRs offer uniform cost advantages across regions, enhancing their competitiveness for global hydrogen production. • SMR offers carbon-neutral, grid-independent desalination solutions. • SMR-powered SWRO yields lower water costs vs. MED and MSF desalination. • Back-pressure steam turbines cut SMR capacity by 28 %, raising LCOE by over 40 %. • Onshore wind and PV systems have higher LCOE and LCOW than SMR-powered SWRO. • SMR enables cost-competitive hydrogen production, boosting global hydrogen economy.