电子顺磁共振（electron paramagnetic resonance，EPR），又称电子自旋共振（electron spin resonance，ESR），是属于自旋1/2粒子的电子在静磁场下发生的磁共振现象。因为类似静磁场下自旋1/2原子核核磁共振的现象，又因利用到电子的顺磁性，故曾称作“电子顺磁共振”。

由于分子中的电子多数是成对存在，根据泡利不兼容原理，每个电子对中的两个电子必为一个自旋向上，另一个自旋向下，所以磁性互相抵消。因此只有拥有不成对电子存在的粒子（例如过渡元素中重金属原子或自由基），才能表现磁共振。

Electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy is a method for studying materials with unpaired electrons. The basic concepts of EPR are analogous to those of nuclear magnetic resonance (NMR), but it is electron spins that are excited instead of the spins of atomic nuclei. EPR spectroscopy is particularly useful for studying metal complexes or organic radicals. EPR was first observed in Kazan State University by Soviet physicist Yevgeny Zavoisky in 1944, and was developed independently at the same time by Brebis Bleaney at the University of Oxford.