英寸汞柱或英寸水银柱（符号：inHg和"Hg）是压强的量度单位。在美国，它仍然用于天气报告、制冷和航空，作为气压单位。

它被定义为在32 °F（0 °C）和标准重力加速度下，1英寸高的水银圆柱所造成的压强。

在旧文献中，一「英寸汞柱」是基于在60 °F（15.6 °C）的水银柱的高度。

在英制单位：1 inHg = 0.491 098 psi，或2.036 254 inHg = 1 psi。

Inches of mercury, (inHg and "Hg) is a unit of measurement for pressure. It is still used for barometric pressure in weather reports, refrigeration and aviation in the United States.

It is defined as the pressure exerted by a circular column of mercury of 1 inch in height at 32 °F (0 °C) at the standard acceleration of gravity.