Allen Kelsey Grammer (born February 21, 1955), best known as Kelsey Grammer, is an American actor best known for his two-decade portrayal of psychiatrist Dr. Frasier Crane in the NBC sitcoms Cheers (nine years) and Frasier (eleven years), and providing the voice of Sideshow Bob on the FOX animated series The Simpsons. He was nominated for Emmys for playing his character on three different sitcoms (the third being a guest appearance on Wings). He has also worked as a television producer, director, writer, and a voice artist.

Grammer was born in Saint Thomas, U.S. Virgin Islands to Sally (née Cranmer), a singer, and Frank Allen Grammer, Jr., a musician and owner of a coffee shop and a bar & grill. He is descended from Massachusetts Governor Thomas Dudley. His parents' marriage ended when he was young; his mother took him to live with her, and he was raised partly in New Jersey by his maternal grandparents, Evangeline Dimmock and Gordon Cranmer.

Grammer's family life has been plagued by tragedies. In 1968, when Grammer was thirteen, his father, whom he had seen only twice since his parents' divorce, was murdered on the front lawn of his home in the U.S. Virgin Islands. In 1975, his sister, Karen, was murdered after being abducted outside a Red Lobster restaurant in Colorado Springs, Colorado, where her boyfriend worked. Grammer has sworn to prevent his sister's murderer from being paroled and in July of 2009 her convicted murderer was denied parole at least in part due to a written letter submitted to the parole board. In 1980, his twin younger half-brothers by his father's second marriage were killed by a shark in a scuba diving accident.