Sinden was born on June 14, 1950 in London, the son of actor Sir Donald Sinden (of Mogambo fame) and wife Diana Mahoney. He had a younger brother, actor Marc Sinden (born in 1954). Sinden began his career in the seventies, acting as a guest star in TV series, and later for full seasons like his role in Crossroads, and performing in theatres. He also met and married Delia Lindsay in 1977, and had two daughters, Kezia and Harriet. Sinden died of lung cancer in London on May 29, 1996, his wife and daughters surviving him.