Ultraviolet radiation (UVR) stimulates local and systemic immunoregulatory effects in a wavelength-dependant manner. Narrowband UVB (NBUVB) phototherapy is a common and effective treatment for inflammatory skin diseases including psoriasis, but its mechanism of action is not fully understood. This study aims to characterise local and systemic changes in mice following NBUVB irradiation. In a model of contact hypersensitivity, a single exposure to 3 J/cm2 NBUVB suppressed the response to an irritant applied at an unirradiated site. Like exposure to solar simulated UV (ssUV), this immune suppressive dose of NBUVB resulted in Langerhans cell depletion and dermal neutrophil infiltration. Mast cells are a key mediator of ssUV-induced immune suppression, but their dermal frequency was not altered by single or repeated exposure to NBUVB. NBUVB irradiation also generated fewer changes in both the plasma lipidome and lymphocyte recirculation compared to ssUV. While NBUVB is a potent local immunomodulator, these findings suggest it has relatively low capacity to induce systemic effects, which has implications for the clinical use of NBUVB in the treatment of a wider range of diseases.