This study examines how digital transformation (DT) reshapes the passenger journey and customer experience (CX) among Korean low-cost carriers (LCCs). Using a qualitative multiple-case design, the research analyzes secondary sources such as official websites, mobile applications, press releases, annual and sustainability reports, and academic literature covering Jeju Air, Jin Air, T’way Air, Air Busan, and Air Seoul. Findings indicate a transition from efficiency-driven digitization to experience-centered digital transformation. Mobile booking and payment, self-service check-in and bag-drop, real-time flight notifications, and chatbot-based after-service enhance passengers’ perceived control, convenience, and responsiveness across all journey stages—search, booking, pre-departure, inflight, and post-flight. Jeju Air and T’way Air demonstrate the highest level of integration through data-enabled personalization and feedback loops, while Jin Air and Air Busan focus on backstage digitization such as e-documentation and predictive maintenance that indirectly enhance reliability. Air Seoul remains marketing-oriented with limited system integration. However, fragmented data architecture and weak journey-level CX governance hinder the realization of a fully connected digital ecosystem. Theoretically, this study conceptualizes digital transformation as a socio-technical mechanism that connects frontstage and backstage processes to enable value co-creation. From a managerial perspective, the findings highlight the need for integrated data and platform management throughout the passenger journey, the enhancement of human-centered digital interaction capabilities, and the establishment of cross-functional governance linking IT, operations, and service design. Overall, these insights provide practical guidance for LCC managers aiming to balance automation with empathy, ensuring that technology-driven services enhance rather than replace human connection in the digital passenger experience.