| Name | Meaning | Gender | Origin |
|---|
| Caitlin | pure | Female | Irish |
| Cari | Flows Like Water | Unisex | Turkish |
| Cassie | Abbreviation of Cassandra. Unheeded prophetess. In Homer's The Iliad Cassandra's prediction of the fall of Troy was unheeded.
| Female | English |
| Cassy | Frivolous | Unisex | English |
| Cat | pure | Female | English |
| Cat | pure | Female | English |
| Catalina | pure | Female | Spanish |
| Catarina | Blessed, Pure, Holy | Unisex | Italian |
| Caterina | Greek, pure | Female | Italian |
| Cathy | Form of the Greek Catherine meaning pure.
| Female | English |
| Cato | all-knowing | Male | Latin |
| Catrina | Blessed, Pure, Holy | Unisex | Irish |
| Caty | | Unisex | Hebrew |
| Ekaterina | Blessed, Pure, Holy | Female | Slavic |
| Kait | Blessed, Pure, Holy | Unisex | English |
| Karen | pure | Female | Danish |
| Kari | curly hair | Male | Norse |
| Karin | Pure | Unisex | Greek |
| Kasia | Pure | Female | Polish |
| Kaska | | Unisex | Hebrew |
| Kat | pure | Female | English |
| Katalina | Lovely Sunset | Unisex | Biblical, Italian |
| Katarina | pure | Female | Czech |
| Kate | Pure | Female | English |
| Katerina | Blessed, Pure, Holy | Unisex | Czechoslovakian |
| Katherine | Pure. Used since third century A.D. Early Latin forms Katerina and Caterina became Katharine and Catherine. French Cateline and English Catlyn came into wider use during medieval period when variants multiplied.
| Female | Greek |
| Kathi | after a character in the Lymond novels by Dorothy Dunnett | Unisex | |
| Kathleen | Innocent
| Female | Anglicized |
| Katia | pure | Female | Russian |
| Katie | Variant of Katherine. Pure.
| Female | English |
| Katina | Pure, Unsullied | Unisex | Greek |
| Katinka | after the character in the movie Zoolander | Unisex | |
| Katka | | Unisex | Hebrew |
| Katrina | Greek, pure | Female | |
| Katy | pure | Female | Short |
| Katy | pure | Female | Short |
| Katya | pure | Female | Russian |
| Kit | Nickname for Christopher. Frontiersman Kit Carson.
| Male | English |
| Kitty | Variant of Katherine. Pure.
| Female | English |
| Kitty | Variant of Katherine. Pure.
| Female | English |
| Kitty | Variant of Katherine. Pure.
| Female | English |
| Trina | German variation of Katherine | Female | Scandinavian |