Abstract: To investigate the effects of starch source and gelatinization treatment on the growth performance and glycolipid metabolism of hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂). Eight isonitrogenous and isolipidic experimental diets containing 20% of either raw or gelatinized starch from corn, wheat, potato, or sweet potato, were formulated and fed to eight groups of juvenile fish across an 8-week feeding period. Starch source did not significantly affect final body weight, specific growth rate, or feed efficiency, but significantly influenced serum biochemistry and hepatic enzyme activities of glycolipid metabolism. The viscerosomatic index was significantly higher in corn and wheat starch groups than in potato and sweet potato starch groups. The sweet potato starch group had lowest muscle lipid content and highest muscle glycogen content (P < 0.05). Serum HDL-C, LDL-C, and AST levels were lowest in corn starch group and highest in wheat starch group. Blood glucose was highest in sweet potato starch group and lowest in potato starch group. Serum ALT was lowest in wheat starch group and highest in sweet potato starch group. Serum insulin and glucagon levels were lowest in potato starch group and highest in corn starch group. Hepatic PK and FBP activities were significantly higher in wheat starch group than in other three groups. Gelatinization treatment significantly affected growth performance, serum components, and enzyme activities of glycolipid metabolism. The raw starch group had significantly higher weight gain rate, specific growth rate, feed efficiency, hepatic protein and lipid contents, serum HDL-C, glucose, and glucagon levels, as well as hepatic FBP and CPT-1 activities, but had significantly lower VSI, HSI, CF, hepatic glycogen, muscle protein, serum TG, TC, AST, ALT, INS, and hepatic PK, PFK, and LPL activities compared to gelatinized starch group. Transcriptomic analysis revealed that gelatinization treatment induced a greater number of differentially expressed genes (DEGs) over starch source treatment. Among them, 645 DEGs were up-regulated and 286 were down regulated in the raw and gelatinized corn starch comparison group, and 635 were up-regulated and 696 were down regulated in the raw and gelatinized potato comparison group. These DEGs are mainly enriched in pathways such as glycolysis / gluconeogenesis and PPAR signaling, indicating that under sufficient starch supply, fish preferentially utilize glucose as energy and promote fatty acid β-oxidation. In conclusion, raw starch, due to its relatively low digestibility, favors gradual starch utilization and promotes growth, whereas gelatinized starch, with its relatively high digestibility, tends to enhance lipid deposition to some extent. This study provides a scientific basis for the rational formulation of starch in fish feed and its improvement of feed utilization.