寄生电容（英语：parasitic capacitance）也称为杂散电容，是电路中电子组件之间或电路模块之间，由于相互靠近，形成的不可避免，同时经常是人们设计时不希望得到的电容，是一种寄生组件。在现实中，所有的电路组件，例如电感组件、二极管和晶体管都具有内部电容，这些电容将使器件的性能与理想情况有所不同。此外，在任意两段导体之间均有非零的电容，这种电容在高频情况中体现得尤为突出，因此在印制电路板设计中必须予以考虑。

In electrical circuits, parasitic capacitance, or stray capacitance is an unavoidable and usually unwanted capacitance that exists between the parts of an electronic component or circuit simply because of their proximity to each other. All actual circuit elements such as inductors, diodes, and transistors have internal capacitance, which can cause their behavior to depart from that of 'ideal' circuit elements. Additionally, there is always non-zero capacitance between any two conductors; this can be significant at higher frequencies with closely spaced conductors, such as wires or printed circuit board traces.