From Wikipedia, the free encyclopedia. Katerina Alexandre "Kat" Graham (born September 5, 1989) is an American actress, singer, dancer, and model. She has appeared in numerous television shows and film productions, as well as music videos. In 2009, she began appearing in a supporting role as Bonnie Bennett in The CW television network show, The Vampire Diaries. Description above from the Wikipedia article Katerina Graham, licensed under CC-BY-SA,full list of contributors on Wikipedia.