德拜（符号为D）是一种CGS制的矢量单位。 它是偶极矩（或称电偶极矩）的非国际制单位（non-SI metric system|metric unit）。这个单位为纪念物理学家彼得·德拜而以其名字命名。德拜被定义为1×10 直流库伦·厘米（statcoulomb-centimeter）。德拜被定义为相距1 Å的等量（10直流库伦）异种电荷间的偶极矩。（在较老的文献中一般用e.s.u.，即“electrostatic unit”的缩写）。德拜是一种较为方便的分子偶极矩的单位。

一般双原子分子的偶极矩在0至11 D的范围内，对称的同原子分子，像是氯分子的偶极矩为零；而高度离子化的物质，例如气态的溴化钾之偶极矩为10.5 D。

The debye (symbol: D) (/dɛˈbaɪ/; Dutch: [dəˈbɛiə]) is a CGS unit (a non-SI metric unit) of electric dipole moment named in honour of the physicist Peter J. W. Debye. It is defined as 1×10 statcoulomb-centimetre. Historically the debye was defined as the dipole moment resulting from two charges of opposite sign but an equal magnitude of 10 statcoulomb (generally called e.s.u. (electrostatic unit) in older literature), which were separated by 1 ångström. This gave a convenient unit for molecular dipole moments.