Fish oil supplementation exerts therapeutic effects on atopic dermatitis (AD). The therapeutic effects and mechanisms of action of solubilized sturgeon oil (SSO) prepared from sturgeon oil in AD were examined. NC/Nga mice were topically treated with house dust mite (HDM) extract to induce AD and were then treated with SSO, which exerted potent therapeutic effects on AD symptoms. SSO reduced epidermal hyperplasia and suppressed mast cell infiltration in the dorsal skin. It significantly reduced total and HDM-specific serum IgE levels in AD mice. SSO significantly downregulated interleukin (IL)-4, IL-5, IL-13, IL-17A, and cyclooxygenase-2, while upregulating IL-10 and tight junction-related proteins filaggrin, claudin-1, occludin, and ZO-1 in AD skin tissues. These results show that SSO exerts therapeutic effects in AD mice by alleviating lesions, downregulating IgE, inflammatory mediators, and Th2 cytokines, and upregulating IL-10 and tight junction-related proteins. Thus, SSO may be a promising natural product for AD treatment.