虔敬主义（英语：Pietism）是17世纪晚期到18世纪中期，发生在路德宗的一次变革所产生的思想。它在新教和圣公会里影响较大。

Pietism (/ˈpaɪᵻtɪsm/, from the word piety) was an influential movement within Lutheranism that combined 17th-century Lutheran principles with the Reformed emphasis on individual piety and living a vigorous Christian life.

It began in the late 17th century, reached its zenith in the mid-18th century, and declined through the 19th century, and had almost vanished in America by the end of the 20th century. While declining as an identifiable Lutheran group, some of its theological tenets influenced Protestantism generally, inspiring the Anglican priest John Wesley to begin the Methodist movement and Alexander Mack to begin the Brethren movement among Anabaptists.