Fish populations in their natural habitats depend on the spawning and recruitment of fingerlings, two processes that are critical to the survival of fish populations. Reproduction is one of the most significant parts of fish biology. To offer a biological foundation for managing the spotted sea bass (Dicentrarchus punctatus) fishery in Bardawil Lagoon, North Sinai, Egypt, this study aimed to explore the reproductive biology of this species. Monthly specimens of the spotted sea bass (n= 2050) were obtained from the commercial catch from selected landing sites of the Bardawil Lagoon from January 2020 to December 2021. The fish sex ratio recorded 1 male: 1.587 females and 1 male: 1.584 females during 2020 and 2021 fishing seasons, respectively. A stability of sex ratio was noticed, whereas the female ratio was 61.3% and the male ratio was 38.7% during both 2020 and 2021 fishing seasons. The gonadosomatic index (GSI) increased progressively from September to February; the highest values were recorded in December at 6.76 and 8.17 for females and 4.46 and 5.59 for males during the two fishing seasons 2020 and 2021, respectively. Thus, the spawning season for the spotted sea bass is between November and February. The length at the first maturity was estimated at an average length of 21.6cm for both sexes. Fecundity was estimated for 78 ripe ovaries ranging between 29475 (15cm in total length and 38.3g in weight) and 621440 eggs (34.7cm in total length and 368.4g in weight). Based on ovarian histological examination, December is the period of maturation. To prevent overfishing and enable female spotted sea bass (D. punctatus) to reproduce, grow, and recruit into the fishery, we suggested permitting the use of mesh sizes larger than those used at Bardawil Lagoon.