Atopic dermatitis (AD) is a chronic inflammatory skin disease stemming from genetic susceptibility and environmental factors. It is characterized by immune dysregulation, increased mast cell activity, elevated levels of immunoglobulin E (IgE), and excessive proinflammatory mediator expression. These factors contribute to hallmark symptoms such as pruritus, erythema, and skin barrier dysfunction. In this study, we investigated the antioxidant and anti-inflammatory effects of Taraxacum mongolicum (WTM) water extract, as well as its skin barrier regulation and immune functions in AD. In the present study, we explored the therapeutic efficacy and underlying mechanisms of WTM in a BALB/c mouse model of AD induced by 2,4-dinitrochlorobenzene (DNCB). Mice were administered WTM orally or topically for 14 consecutive days. The results demonstrated that WTM treatment significantly alleviated clinical severity, showing reductions in skin lesion scores, epidermal thickness, mast cell infiltration, and scratching behavior, compared to the DNCB-treated group. Mechanistically, WTM reduced serum levels of IgE and proinflammatory cytokines (IL-4, IL-6, IL-1β, TNF-α, and IL-31) while suppressing the expression of the JAK/STAT/TSLP signaling pathway in skin tissues. Furthermore, WTM inhibited the TLR4/NF-κB and MAPK pathways and enhanced antioxidant defense by elevating superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx) activities. These findings indicate that WTM attenuates DNCB-induced AD progression in mice, likely through the dual modulation of inflammatory signaling and oxidative stress. These findings suggest that WTM may modulate the immune response and alleviate AD symptoms by inhibiting the TLR4/NF-κB, MAPK, and JAK/STAT/TSLP pathways.