MI5 is headed by the Director General, currently Ken McCallum. The role of the Director General was set out in the Security Service Act 1989.
He is personally responsible for:
In discharging these responsibilities, the Director General is assisted by internal mechanisms designed to ensure that our work abides by the principles that:
Ken McCallum is the current Director General of MI5. He is the eighteenth Director General of MI5 since the post was created in 1909 (see former Directors General for a list of his predecessors). He succeeded Sir Andrew Parker in April 2020.
Ken McCallum is an MI5 officer with almost 25 years of experience across the full spectrum of the organisation's national security and intelligence work.
His first ten years was focussed on Northern Ireland-related terrorism. Senior operational roles in countering Islamist extremist terrorism followed, and a period leading on cyber security, where he expanded MI5 engagement with the private sector.
In 2012, Ken took charge of all counter terrorism investigations and risk management in the run-up to, and during, the London Olympics. After the Games, he embarked on a secondment to the Department for Business, Innovation and Skills (now BEIS) leading on digital issues, building his experience beyond the national security domain. Following his return to MI5 he retained links to the wider public sector, serving for three years as a Non-Executive Director on the board of the Nuclear Decomissioning Authority.
In April 2015, Ken took on the role of Director General Strategy, focussing on shaping new legislation and further strengthening MI5's partnerships with SIS and GCHQ.
Ken was appointed Deputy Director General of MI5 in April 2017, with responsibility for all of MI5's operational and investigative work.
Ken led MI5's strategic response to the 2017 terrorist attacks, setting up the joint MI5 and Police 'Operational Improvement Review', as overseen by Lord Anderson QC, and then driving forward the implementation of its recommendations. Important changes included new ways of working with traditional and new partners, and MI5 taking on responsibilities for detecting and countering Right-Wing Terrorism.
In 2018, Ken took charge of the MI5 response to the attempted assassination of Sergei Skripal, within the unprecedented UK-led international response from intelligence allies.
Ken grew up in Glasgow, and holds a degree in Mathematics from Glasgow University. His out-of-work life is dominated by trying to be an active father. When work/parenting allows, he enjoys hiking in mountains.