This study presents an atomistic simulation of thermoelectric properties in cove-edged graphene nanoribbons (CGNRs) using the nonequilibrium Green's function method. Unlike gapless zigzag graphene nanoribbons (ZGNRs), CGNRs exhibit a noticeable bandgap, which can be modulated by varying three structural parameters: width (N), distance between adjacent coves (m), and shortest offset (n). This modulation enables the transition from semiconducting to semi-metallic behavior. CGNRs have lower phonon thermal conductance compared to ZGNRs due to less dispersive phonon bands and fewer phonon channels. Modulation of CGNRs leads to over tenfold improvement in the maximum ZT (thermoelectric figure of merit) compared to ZGNRs, attributed to enhanced Seebeck coefficients and reduced phonon thermal conductance. The study shows that CGNRs can significantly improve thermoelectric performance, making them promising candidates for high-performance thermoelectric devices. The results highlight the importance of structural parameters in controlling thermoelectric properties and suggest that CGNRs could be useful for designing efficient thermoelectric materials.This study presents an atomistic simulation of thermoelectric properties in cove-edged graphene nanoribbons (CGNRs) using the nonequilibrium Green's function method. Unlike gapless zigzag graphene nanoribbons (ZGNRs), CGNRs exhibit a noticeable bandgap, which can be modulated by varying three structural parameters: width (N), distance between adjacent coves (m), and shortest offset (n). This modulation enables the transition from semiconducting to semi-metallic behavior. CGNRs have lower phonon thermal conductance compared to ZGNRs due to less dispersive phonon bands and fewer phonon channels. Modulation of CGNRs leads to over tenfold improvement in the maximum ZT (thermoelectric figure of merit) compared to ZGNRs, attributed to enhanced Seebeck coefficients and reduced phonon thermal conductance. The study shows that CGNRs can significantly improve thermoelectric performance, making them promising candidates for high-performance thermoelectric devices. The results highlight the importance of structural parameters in controlling thermoelectric properties and suggest that CGNRs could be useful for designing efficient thermoelectric materials.