磁倾角（Magnetic dip）是在地球表面磁场与地平线所成的夹角。一般来说，北半球的磁倾角为正，南半球的磁倾角为负。将磁倾角为零的地方连起来，此线称为磁倾赤道，与地球赤道比较接近。

Magnetic dip, dip angle, or magnetic inclination is the angle made with the horizontal by the Earth's magnetic field lines. This angle varies at different points on the Earth's surface. Positive values of inclination indicate that the magnetic field of the Earth is pointing downward, into the Earth, at the point of measurement, and negative values indicate that it is pointing upward. The dip angle is in principle the angle made by the needle of a vertically held compass, though in practice ordinary compass needles may be weighted against dip or may be unable to move freely in the correct plane. The value can be measured more reliably with a special instrument typically known as a dip circle.