Painswick Stream is a small river in Gloucestershire, England. It is a tributary of the River Frome, and flows generally southwards, passing around the village of Painswick and through the town of Stroud. It used to join the Frome at its mouth, but was diverted into the then-derelict Stroudwater Navigation as part of a flood relief scheme in the 1950s. Despite its small size, it has been used to power a significant number of mills, many of which were associated with cloth manufacture until the industry was hit by a series of depressions in the 1820s and 1830s. Some found other uses, being used for grinding corn and for the manufacture of walking sticks and umbrella sticks, another prominent local industry. Many were subsequently demolished, but a number survive which have been granted listed building status.
In Stroud, the river flows through Stratford Park where there is an arboretum, created by the Watts family of brewers. The park has been managed by Stroud District Council since 1936, and two bridges carry a model railway over the river. The Stroudwater Navigation through Stroud has been restored, and the water from the river and from the Slad Brook, which was also diverted into the canal, now powers a water turbine generating electricity, the sale of which helps to fund the maintenance of the canal. The water quality of the river is measured by the Environment Agency, and its ecological status is good, although its chemical status, in common with most rivers in England, is bad, due to the presence of chemicals which had not previously been included in the assessment.