Black soldier fly larvae (BSFL), lesser mealworm (LMW) and yellow mealworm (YMW) are suggested as a sustainable novel protein source which could improve growth and gastrointestinal function and health of weaned piglets. The objective of this study was to investigate the effects of BSFL, LMW and YMW in diets for weaned piglets on growth performance and gut health-related parameters. A total of 96 crossbred [(Landrace × Yorkshire) × Duroc] male piglets weaned at 28 days of age with an average weight of 6.6 ± 0.5 kg were used. For 2 weeks, piglets were fed a control diet (CTRL) with 14% enzyme-treated soybean meal or diets containing 2.66% enzyme-treated soybean meal and dried meal of defatted BSFL larvae, LMW and YMW at 8.35, 9, and 7.66% respectively. In each diet, 24 piglets were randomly allocated in individual pens. For all the growth performance parameters, no differences were observed among dietary treatments. All the treatments showed similar values of Immunoglobulin A (IgA). The concentration of D-lactate was not affected by treatments. Piglets fed LMW and YMW diets demonstrated a lower concentration of diamine oxidase (DAO; 321 and 309 ng/ml, respectively) than in the CTRL diet (382 ng/ml, P<0.05). Enterococci and lactobacilli in digesta were not different among treatments. Lactic acid varied between 48.6 and 63.4 g/100 g of total organic acid with the highest values found for the BSFL group and the lowest values found for the CTRL group (P=0.004). There was no difference among dietary treatments in the concentration of total short-chain fatty acids in the colon digesta. In conclusion, the inclusion of BSFL, LMW and YMW in weaned piglet diets in expense of enzyme-treated soybean meal showed similar effect on growth performance and most gut health parameters as compared to the CTRL diet. Reduced plasma DAO indicated protection of the intestinal mucosa barrier function when fed the mealworm-included diets. Meal of defatted BSFL larvae, LMW and YMW can be good alternatives to conventional protein sources and can be included in the balanced diet of weaned piglets.