The Hook and Cod wars (Dutch: Hoekse en Kabeljauwse twisten) comprise a series of wars and battles in the County of Holland between 1350 and 1490. Most of these wars were fought over the title of count of Holland, but some have argued that the underlying reason was because of the power struggle of the bourgeois in the cities against the ruling nobility.

The Cod faction generally consisted of the more progressive cities of Holland. The Hook faction consisted for a large part of the conservative noblemen.

The origin of the name "Cod" is uncertain, but is most likely a case of reappropriation. Perhaps it derives from the arms of Bavaria, that look like the scales of a fish. The Hook refers to the hooked stick that is used to catch cod. Another possible explanation is that as a cod grows it tends to eat more, growing even bigger and eating even more, thus encapsulating how the noblemen perhaps saw the expanding middle classes of the time.