The actor announced the news by posting a notice in British newspaper The Times.
"The engagement is announced between Benedict, son of Wanda and Timothy Cmberbatch of London, and Sophie, daughter of Katharine Hunter of Edinburgh and Charles Hunter of London," the announcement read.
A spokesman for the 38-year-old star also confirmed the news, saying, "I am delighted to confirm this morning's announcement that Benedict Cumberbatch and Sophie Hunter are engaged."
The couple is yet to announce a wedding date.
Hunter, 36, an Oxford graduate, is a theatre director and actress.
