In this study, we explore the influence of divacancies (DVs) on the electronic structure and thermoelectric properties of zigzag buckling silicene nanoribbons (ZBSiNRs). We employ the tight-binding approach and determine the electronic structure by numerically diagonalizing a tight-binding Hamiltonian with various configurations of hopping parameters. We investigate impacts of an external electric field perpendicular to the material surface on the band gap’s width and the Seebeck coefficient’s maximal value. Our results reveal that ZBSiNRs retain their metallic nature even in divacancies. However, the dispersion curves of the flat bands transform into upward-sloping bands. Additionally, our calculations indicate that introducing DVs near the ribbon edges can enhance the conductance of the ribbons. Notably, the width of the band gap and the Seebeck coefficient of the ZBSiNRs exhibit an almost linear increase in response to an applied electric field.