This study evaluated the fit of a one-piece dress using a 3D-printed dress form designed to reflect the body shape of middle-aged women and examined its potential for practical application by comparing the results with those from a 3D virtual fitting program. Therefore, a dress form was created based on the body measurements of middle-aged women using 3D body scanning and 3D printing, and an actual one-piece dress was fitted onto it. The same pattern was then simulated in a 3D virtual fitting program. A subsequent visual assessment was performed to compare and analyze the similarity between the 3D virtual fitting and actual fitting results. The analysis revealed that the 3D-printed dress form more accurately replicated the body characteristics of middle-aged women, making it advantageous for evaluating actual wearing comfort and garment fit. In contrast, the virtual fitting program demonstrated limitations in detailed expressions of elements such as wrinkles in specific body areas and fabric properties, resulting in lower consistency with real-world fitting outcomes compared to the dress form. This study confirmed that the 3D-printed dress form for middle-aged women can enhance accuracy in both fit evaluation and garment production processes. Future studies should focus on developing dress forms that accommodate diverse body types and refining virtual fitting technologies to enable more precise garment simulation and evaluation.