Oyaksoongi-San (OYSGS), which is a combination of 11 herbal ingredients, has long been used in Asia to relieve symptoms of various diseases conditions, including vomiting and diarrhea. In this study, we assessed the protective efficacy of OYSGS in a murine model of asthma induced by ovalbumin (OVA) and explored potential molecular mechanisms. Male C57BL/6 mice were sensitized with OVA and airway challenged with OVA (1% w/v in PBS) for 1 h. OYSGS (100, 300, and 500 mg/kg once daily) was administered for 6 days by oral gavage. Our results revealed that OYSGS significantly decreased the number of inflammatory cells and reduced the concentrations of interleukin (IL)-5 and IL-13 in bronchoalveolar lavage fluid (BALF). Histological analyses showed that OYSGS substantially decreased inflammation and mucus hypersecretion in the airway. Further analyses revealed that OYSGS effectively reduced oxidative stress, as shown by downregulation of malondialdehyde (MDA) and upregulation of total glutathione (GSSG/GSH), and markedly suppressed the phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK). Together, these results suggest that OYSGS effectively inhibits the airway inflammatory responses, mucus secretion, and oxidative stress induced by OVA.