It plans to increase it's staff numbers by up to 50% by 2020
MI6 is to recruit up to 1,000 extra staff to fight the modern threats facing the UK.
The Secret Intelligence Service has been given more money to expand its operations.
There is no detail on what positions are being advertised, but it's thought the new personnel will be experts in cyber, data collection, languages and foreign analysis.
It will take the size of MI6 from about 2,500 staff to as many as 3,500 by 2020.
It announced the planned recruitment of 1,900 extra staff to the intelligence agencies - with MI6 to get the bulk of that increase.
Although an exact number has never been confirmed, it is understood to be accurate.
Alex Younger, the Chief of the Secret Intelligence Service, spoke alongside his counterparts from the US, Australia and Canada at an event in Washington DC on Wednesday.
Although he didn't speak about the increased recruitment, he expanded on the challenges facing Western intelligence agencies.
Mr Younger said there is a "deepening sectarian divide in the Middle East", adding: "There are some deep social, economic and demographic drivers to the phenomenon we know as terrorism. Allied with the emergence state failure, I think that regrettably this is an enduring issue."
But he said friendly intelligence agencies are working better, together, to deal with the threat of terrorism.
The digital age has broken down physical and geographical barriers and ideologies can spread easily through the internet, with the cyber world acting as both a great enabler and a great disrupter of the intelligence mission.
"I think the information revolution fundamentally changes our operating environment," Mr Younger told the event.
"In five years' time, there will be two sorts of intelligence agencies: those who understand this fact and have prospered and those who don't and haven't. And I'm determined that MI6 will be in the former category."
"C", as he his nicknamed, also said intelligence agencies could serve as a valuable link to traditionally hostile countries.
He explained: "We need to find a way of messaging these countries and communicating with them. So often the vector between the security services, intelligence services, is one of the most important and I certainly stand ready with my government to communicate and perhaps send the hard messages. I think these conversations are a good way to do it, because they're not attended by publicity."
In order to apply for a job in MI6, one or both of your parents must be or have been a British citizen, and you should have spent the majority of the last decade living inside Great Britain.
Full details of the job specs can be found here.