This category contains articles about postage stamps and stamp issues that are notable for unintended deviations in their design or production. These include errors and varieties involving printing, colour, paper, watermarks, gum or perforation, as well as recurring plate varieties and other philatelic oddities.

It does not include stamps that were merely issued, used or withdrawn in error without an unintended variation in the stamp itself.

Wikimedia Commons has media related to Stamp oddities and errors.