This study aimed to investigate the dietary effects of Quillaja saponin (QS) and seaweed (SW) on growth performance, fecal score, and gas emissions in weaning pigs. A total of 120, 21-day old crossbred ([Yorkshire�×�Landrace] × Duroc) weaning pigs were randomly assigned to three treatment groups. These dietary treatments consisted of (1) TRT1: CON (basal diet), (2) TRT2: CON + 200�mg/kg QS, and (3) TRT3: CON + 500�mg/kg SW. Pigs were raised in 10 replicate pens per treatment (two males per pen and two females per pen) for 5 weeks based on body weight and sex. The inclusion of QS significantly (p�<�0.05) increased average daily gain (ADG) and average daily feed intake (ADFI) during the overall period compared to the control diet. Moreover, the tendency to increase ADG was found at weeks 1 and 5, whereas ADFI showed a tendency to increase at week 1 with the supplementation of QS compared to the CON diet. However, the feed conversion ratio, fecal score, and gas emission failed to show significant effects throughout the experiment. In summary, QS has a beneficial effect on the growth performance of weaning pigs without any negative effect on gas emission and fecal score.