Jonkheer

' (female equivalent: '; in the masculine only; jonkvrouw is used in the feminine, even in French; ) is an honorific in the Low Countries denoting the lowest rank of the nobility. Currently in the Netherlands, jonkheer in general concerns a prefix used by the untitled nobility. In Belgium, this is the lowest title within the nobility system, recognised by the Court of Cassation. It is the cognate and equivalent of the German noble honorific , which was historically used throughout the German-speaking part of Europe, and to some extent also within Scandinavia.

The abbreviation of the honorific is jhr., and that of the female equivalent jkvr., which is placed before the given name and titles. When using the French translation écuyer, it is placed after the full name, separated by a comma, like the English esquire, but in Belgium it is not a courtesy title and neither does it indicate a lawyer (for whom the postfix ", avocat" or the prefix "Maître" would be used instead, depending on context).