This study investigates the Josephson diode effect (JDE) in a superconductor/quantum dot (QD)/superconductor junction with Rashba spin-orbit interaction (RSOI) and an external magnetic field. Using the Keldysh non-equilibrium Green's function technique, the researchers calculate the Josephson current and demonstrate that the JDE is significantly enhanced in the presence of RSOI and a magnetic field. The rectification coefficient (RC) is found to be highly tunable by the magnetic field and RSOI, with the highest RC reaching up to 70% under optimal conditions. The study shows that the QD-based Josephson diode (JD) can be controlled by an external gate voltage, enabling a large JDE. The results indicate that the JDE is not strictly dependent on chirality or magnetic field, but their combined presence enhances the rectification. The study also highlights the potential of the QD-based JD as a component in superconducting devices. The findings suggest that the JDE can be achieved in various quantum materials and systems, and the tunability of the external magnetic field, RSOI, and gate voltage makes the QD-based JD a promising candidate for efficient switching devices.This study investigates the Josephson diode effect (JDE) in a superconductor/quantum dot (QD)/superconductor junction with Rashba spin-orbit interaction (RSOI) and an external magnetic field. Using the Keldysh non-equilibrium Green's function technique, the researchers calculate the Josephson current and demonstrate that the JDE is significantly enhanced in the presence of RSOI and a magnetic field. The rectification coefficient (RC) is found to be highly tunable by the magnetic field and RSOI, with the highest RC reaching up to 70% under optimal conditions. The study shows that the QD-based Josephson diode (JD) can be controlled by an external gate voltage, enabling a large JDE. The results indicate that the JDE is not strictly dependent on chirality or magnetic field, but their combined presence enhances the rectification. The study also highlights the potential of the QD-based JD as a component in superconducting devices. The findings suggest that the JDE can be achieved in various quantum materials and systems, and the tunability of the external magnetic field, RSOI, and gate voltage makes the QD-based JD a promising candidate for efficient switching devices.