-ka is a Germanic and Old High German diminutive suffix used to create diminutive forms of names. A variant form is -ko.
Originally, it was an ending used for both genders. Today, it is only used for female names.
In Old High German it changed to -cha which later merged with another Germanic diminutive -īn (see also -chen).
In Frisian and Low German it changed to -ke, sometimes shortened to -k. If Latinised, those forms changed back to -ka.
In Finnish and Sami, -ka/-ká/-kka/-kká can be variant forms of -ke.
Spelling variants are -ca, -cka, -kka, -qa.
List of Names with the suffix -ka