The coat of arms of Hoorn is a coat of arms that has been in use since the middle ages. Although over time it underwent some changes, there has been no change to the coat of arms since it was acknowledged in use by the in 1816. At present, in the original form, it is the coat of arms of the municipality of Hoorn. The current municipality was formed in 1979 by merging the city of Hoorn with the villages Zwaag and ; it was decided to use the old coat of arms as coat of arms of the new municipality.