As always, the letter K is one with a sparser set of saints to chose from. However, that does not mean that the field is devoid of entries. Our saint for today hails from the Eastern Church, Saint Kassia:
Kassia (Greek: Κασσιανή Kassiani; 805/810 – before 865) was a Byzantine abbess, poet, composer, and hymnographer. She is one of the first medieval composers whose scores are both extant and able to be interpreted by modern scholars and musicians. Approximately fifty of her hymns are extant and twenty-three are included in Orthodox Church liturgical books. The exact number is difficult to assess, as many hymns are ascribed to different authors in different manuscripts and are often identified as anonymous.
In addition, some 789 of her non-liturgical verses survive. Many are epigrams or aphorisms called “gnomic verse”, for example, “I hate the rich man moaning as if he were poor.”
Kassia is notable as one of only two Byzantine women known to have written in their own names during the Middle Ages, other being Anna Comnena.
More can be learned about her at her wiki, found here.