This paper presents the calculation of all leading-twist quark generalized parton distributions (GPDs) of the proton at nonzero skewness within the basis light-front quantization (BLFQ) framework. The BLFQ approach uses a light-front Hamiltonian with a three-dimensional confinement potential and a one-gluon exchange interaction to generate the proton's light-front wave functions (LFWFs). These LFWFs are then used to compute the GPDs, which encode the three-dimensional structure of the proton. The results show that the GPDs exhibit similar qualitative behavior to other theoretical calculations. The GPDs are analyzed in the boost-invariant longitudinal position space, defined as σ = (1/2)b⁻P⁺, which is the Fourier conjugate of the skewness. The GPDs in σ-space display diffraction patterns, analogous to those observed in optical diffraction. The study also highlights the importance of GPDs in understanding exclusive scattering processes, such as deeply virtual Compton scattering (DVCS), and their role in future experiments at facilities like the Electron-Ion Collider (EIC). The results demonstrate that the BLFQ framework provides a nonperturbative method for calculating GPDs and offers insights into the structure of the proton. The findings are consistent with other theoretical models and provide a foundation for further research into GPDs and their applications in particle physics.This paper presents the calculation of all leading-twist quark generalized parton distributions (GPDs) of the proton at nonzero skewness within the basis light-front quantization (BLFQ) framework. The BLFQ approach uses a light-front Hamiltonian with a three-dimensional confinement potential and a one-gluon exchange interaction to generate the proton's light-front wave functions (LFWFs). These LFWFs are then used to compute the GPDs, which encode the three-dimensional structure of the proton. The results show that the GPDs exhibit similar qualitative behavior to other theoretical calculations. The GPDs are analyzed in the boost-invariant longitudinal position space, defined as σ = (1/2)b⁻P⁺, which is the Fourier conjugate of the skewness. The GPDs in σ-space display diffraction patterns, analogous to those observed in optical diffraction. The study also highlights the importance of GPDs in understanding exclusive scattering processes, such as deeply virtual Compton scattering (DVCS), and their role in future experiments at facilities like the Electron-Ion Collider (EIC). The results demonstrate that the BLFQ framework provides a nonperturbative method for calculating GPDs and offers insights into the structure of the proton. The findings are consistent with other theoretical models and provide a foundation for further research into GPDs and their applications in particle physics.