<p>Superhydrophobic surface technology, inspired by natural surfaces such as lotus leaves, has been attracting attention for its ability to repel water droplets. However, demand for “omniphobic” surfaces that can even repel oily liquids with low surface tension is growing. A re-entrant structure design with a protruding top plays a key role in achieving this omniphobic performance to prevent droplets from getting caught on the top of the structure. This study comprehensively reviews the design principles and manufacturing technology of omniphobic surfaces using polymer-based re-entrant structures. Polymer materials are suitable for creating omniphobic surfaces due to their excellent processability and ability to implement complex microstructures, allowing them to be utilized in various applications, such as antifouling, self-cleaning, and anti-icing. First, we examined the wetting theory of the liquid-solid interface and the operating principle of the re-entrant structure. We also summarized the characteristics of major polymer materials and examples of omniphobic surface implementation. Additionally, we introduce the principles and latest research trends of top-down processes through replica molding and bottom-up processes through 3D printing as representative methods for fabricating re-entrant polymer structures. This review summarizes recent advances in polymer-based omniphobic surface technologies and provides insights into future research directions.</p> Graphical abstract <p></p>