Atopic dermatitis (AD) is a chronic inflammatory skin disease caused by immune hypersensitivity reaction. The cause of AD is unclear, but its symptoms have a negative effect on quality of life; various treatment methods to alleviate these symptoms are underway. In the present study, we aimed to evaluate in vitro antioxidant and anti-inflammatory effects of Rubus coreanus water extract (RCW) on AD. Total phenolic compounds and flavonoid content of RCW were 4242.40 ± 54.84 mg GAE/g RCE and 1010.99 ± 14.75 mg CE/g RCW, respectively. RCW reduced intracellular reactive oxygen species level and increased the action of antioxidant enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase in tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ)-stimulated HaCaT cells. Moreover, mRNA expression of the pro-inflammatory cytokines, including TNF-α, interleukin-1β, and interleukin-6, was downregulated by RCW in the TNF-α/IFN-γ-stimulated cells. The levels of inflammatory chemokines (thymus- and activation-regulated chemokine; eotaxin; macrophage-derived chemokine; regulated on activation, normal T-cell expressed and secreted; and granulocyte-macrophage colony-stimulating factor) and intercellular adhesion molecule-1 were decreased in the TNF-α/IFN-γ-stimulated HaCaT cells after RCW treatment. Additionally, the mRNA expression levels of filaggrin and involucrin, proteins that form the skin, were increased by RCW. Furthermore, RCW inhibited the nuclear factor kappa-light-chain-enhancer of the activated B cells pathway in the TNF-α/IFN-γ-stimulated HaCaT cells. Collectively, the present investigation indicates that RCW is a potent substance that inhibits AD.