Purpose This study aimed to investigate the effects of robotic gait training combined with a 3D-printed custom orthosis on the 10-Meter Walking Test (10MWT), Timed Up & Go Test (TUG), and Functional Gait Assessment (FGA) in a hemiparetic stroke patient. Methods A single stroke patient participated in this study, which employed a Single-Subject Research Design with an A-B-A’ structure. The participant underwent robotic gait training and engaged in independent walking training indoors for 30 minutes while wearing the 3D-printed custom orthosis. The total duration of the study, including the intervention phase, was 15 days. Results The average values for the 10MWT were as follows: Baseline, 14.92 ± 0.41 sec; Intervention, 12.00 ± 0.43 sec; and Retention, 11.55 ± 0.43 sec. The average TUG test times were Baseline, 31.70 ± 0.13 sec; Intervention, 25.52 ± 2.52 sec; and Retention, 23.70 ± 0.38 sec. In the FGA, the total score increased by 1 point, reaching a final score of 6. Conclusion These findings suggest that robotic gait training combined with a 3D-printed custom orthosis may have a greater positive impact on 10MWT, TUG, and FGA outcomes in stroke patients compared to lower-limb robotic therapy alone.