Brottby is a locality situated in Vallentuna Municipality, Stockholm County, Sweden with 262 inhabitants in 2018.

In the north, Brottby borders Sundby and Libby in the old Garns parish.

Brottby is surrounded by a beautiful cultural environment and important historical land such as Långhundraleden, ancient remains and a rich bird life.

[4] Brottby kvarn is an eight-sailed paltrok mill (skenkvarn), an unusual type of windmill where the windmill body is supported on a ring of rollers on which it rotates to bring the sails into the wind.

This article about a location in Stockholm County, Sweden is a stub.