维恩位移定律（Wien's displacement law）是物理学上描述黑体电磁辐射能流密度的峰值波长与自身温度之间反比关系的定律，其数学表示为：

式中

光学上一般使用纳米（nm）作为波长单位，则
b = 2.897 7721(26) × 10 nm K.

Wien's displacement law states that the black body radiation curve for different temperatures peaks at a wavelength inversely proportional to the temperature. The shift of that peak is a direct consequence of the Planck radiation law which describes the spectral brightness of black body radiation as a function of wavelength at any given temperature. However it had been discovered by Wilhelm Wien several years before Max Planck developed that more general equation, and describes the entire shift of the spectrum of black body radiation toward shorter wavelengths as temperature increases.