A European seabass (Dicentrarchus labrax) weaning trial was conducted from the 30th to the 45th day post-hatching (dph). Larvae aged 3 to 30 dph were reared and fed in the same 2m² tank. In this experiment, several hepatic enzymes and antioxidant parameters were examined, including catalase (CAT), superoxide dismutase (SOD), and total antioxidant capacity (TAC) in larvae subjected to five treatments: control (G); solid-state fermented control (GF); marine synbiotic supplemented (MS); marine synbiotic solid-state fermented (MSF); and marine synbiotic solid-state fermented and resupplemented (MSSF) microdiets. The early weaned larvae fed MS and MSF exhibited significantly greater growth in length during both the 5-45 dph and 30-45 dph periods compared to the other weaning microdiets. Furthermore, larvae fed the MSF microdiet showed significantly better weight growth performance during both periods than those fed the other microdiets. Larvae consuming MS demonstrated the highest activities of glucose, albumin, alkaline phosphatase (ALP), and acid phosphatase (AP). In contrast, larvae consuming the MSF microdiet exhibited notably higher globulin activity. The larvae fed G and GF showed elevated CAT and SOD total activities, while those fed G presented significantly high specific activities of CAT and SOD. Notably, larvae consuming MS revealed the highest total TAC, while those fed MS and MSF displayed the greatest specific TAC activities. In conclusion, synbiotics supplemented or solid-state fermented microdiets enhanced the growth, survival, and antioxidant capacity of the European seabass larvae.