PURPOSE: This study aimed to develop a smartphone mobile application-based supportive return to work (RTW) program for cancer survivors and evaluate its effects on their RTW, fatigue, stress, and quality of working life. This program was developed through a comprehensive process involving literature review, interviews with cancer survivors, and consultations with experts. METHODS: A non-equivalent control group pre- and post-test design was used, with 41 participants assigned to the experimental (n = 18) and control (n = 23) groups based on recruitment timing. The experimental group received a 6-week smartphone mobile application-based supportive RTW program comprising "Counseling and Education" and "Self-Management." Participants completed assessments of decent RTW, fatigue, stress, and quality of working life at baseline and 6 months later. The experimental group completed an additional post-program completion survey. RESULTS: During the 6-week program, no experimental group participants dropped out. The program's impact on decent RTW remains unclear. Fatigue (F = 2.52, p = 0.095) and quality of working life (F = 0.86, p = 0.434) did not show statistically significant differences. However, there was a significant reduction in stress (F = 4.59, p = 0.017). CONCLUSION: The smartphone application-based RTW program, focusing on self-management and counseling, effectively reduced participants' stress levels. To further evaluate the effectiveness of the program, a more diverse range of interventions and ongoing programs should be implemented. IMPLICATIONS FOR CANCER SURVIVORS: This study underscores the importance of tailored digital interventions to support the RTW of cancer survivors. The use of mobile smartphone applications allows temporal and spatial flexibility in program participation. Interventions involving various activities should be implemented to ensure ongoing participation.