Usability testing is significant in software development as it provides insights into user interactions, identifying areas where users may struggle to navigate or utilize a system effectively. Conducting usability tests helps developers understand real-world user behaviors and preferences, allowing them to refine interfaces and functionalities before launch. This process leads to improved user satisfaction, increased adoption rates, and reduced support costs. By incorporating usability testing early in the development cycle, teams can ensure the final product aligns with user expectations and delivers a positive user experience.