Katerina Alexandre Hartford Graham (born September 5, 1989) is a Swiss-born American actress, singer, dancer and model. She is best known for her role as Bonnie Bennett on The CW supernatural drama series The Vampire Diaries. Her film credits include The Parent Trap (1998), 17 Again (2009), The Roommate (2011), Honey 2 (2011), Addicted (2014) and All Eyez on Me (2017). In music, Graham was previously signed to A&M/Octone and Interscope Records, and has released two extended plays and two studio albums.
She is also known as Katerina Alexandre Hartford "Kat" Graham and Kat Graham.