‘Seolhyang’ strawberry is harvested before it is fully ripened and treated with CO2 to extend the shelf-life. However, the volatile changes in the ‘Seolhyang’ strawberry after short-term CO2 treatment have not been investigated, although the volatile profile is an important quality attribute. Herein, we investigated the effect of short-term high CO2 treatment on the changes in the composition of volatile compounds in ‘Seolhyang’ strawberries at two ripening stages (i.e., half-red and bright-red) during cold storage using headspace solid-phase microextraction and gas chromatography-mass spectrometry. Furthermore, the effect of CO2 treatment on fruit quality with respect to the aroma was investigated. A total of 30 volatile compounds were identified. Storage increased the volatile compound concentrations, and the total concentration of volatiles in the CO2-treated strawberries was lower than that of the untreated strawberries during storage. The production of some characteristic strawberry volatiles (e.g., 4-methoxy-2,5-dimethyl-3(2H)-furanone) was inhibited in CO2-treated strawberries. However, CO2 treatment helped maintain the concentrations of hexanal and 2-hexenal, which are responsible for the fresh odor in strawberries. Interestingly, CO2 treatment suppressed the production of off-odor volatiles, acetaldehyde, and hexanoic acid during strawberry storage. Thus, short-term CO2 treatment may help maintain the fresh aroma of strawberries during cold storage.