Weanling piglets, with immature immune system and physiological functions, often experience post-weaning diarrhea. This study investigated the effects of combined supplementation of live yeast and yeast postbiotics on the growth performance, antioxidant capacity and intestinal health of weaned piglets. A total of 224 weaned piglets (22 days old) were randomly assigned to four groups: a basal diet (CON) or the same diet supplemented with 1600 ppm zinc oxide (ZnO), high-dose live yeast and yeast postbiotics (LYYP-H), or low-dose live yeast and yeast postbiotics (LYYP-L). The trial lasted 28 days, with diets divided into 2 phases. The results showed that dietary combined supplementation with live yeast and yeast postbiotics did not significantly affect the average daily gain (ADG), average daily feed intake (ADFI), or the diarrhea rate (p > 0.05). However, dietary combined supplementation with live yeast and yeast postbiotics significantly enhanced fecal consistency in piglets (p < 0.05). Moreover, dietary combined supplementation with live yeast and yeast postbiotics significantly improved representative antioxidant indices, notably superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and strengthened immune capabilities; additionally, a marked improvement in intestinal morphology was observed (p < 0.05). In conclusion, the combination of live yeast and yeast postbiotics can improve antioxidant capacity and intestinal health and show the potential to replace high doses of ZnO during the first two weeks post-weaning.