• The review systematically compares interface engineering strategies for shuttle mitigation across Li–S, Na–S, and K–S batteries, highlighting both common principles and system-specific challenges.
• Key differences in metal-ion radii, solvation energies, and redox kinetics necessitate tailored interface designs for Na–S and K–S systems to achieve effective shuttle suppression.
• Functional separators, interlayers, and solid-state electrolytes are identified as promising internal interface engineering approaches to inhibit polysulfide shuttling and enhance battery performance.
• The review proposes multifaceted solutions for shuttle-free operation, providing a roadmap for the development of next-generation alkali metal-sulfur batteries.