Alex Younger, who oversaw MI6's work on counter-terrorism in the run up to the London Olympic Games 2012, will take over the post next month.
The 51-year-old succeeds Sir John Sawers, who is stepping down as chief of the country's spy agency.
The appointment marks continuity of policy and strategy as he has served as the right-hand man for Sawers.
Foreign secretary Philip Hammond said Younger, described as a career SIS officer, would bring "a wealth of relevant experience".
Younger, who joined SIS in 1991, has overseen MI6's intelligence operations across the world for the past two years.
He said: "I am delighted and honoured to become chief of SIS and lead one of the best intelligence agencies in the world. Our dedicated staff work tirelessly against an array of threats that this country faces. They do so in close partnership with both MI5 and GCHQ with whom I am looking forward to co-operating closely."
In a biography provided by the UK Foreign and Commonwealth Office, Younger is said to enjoy music, sailing and mountaineering.
His is married with children.
"Alex brings a wealth of relevant experience including his work in Afghanistan and helping keep the country safe during London 2012 Olympics."
Sir John announced in June that he would be stepping down from the role.
He said: "I'm delighted that my colleague and friend is taking over from me. He has played a vital part alongside me in modernising SIS and ensuring that the Service is in the best possible shape to play our part in defending the country's security and our values."
