Channel 4’s Chief Operating Officer, Jonathan Allan, will serve as interim CEO while the Board undertake a comprehensive recruitment process over the coming months.

Dawn Airey, Channel 4 Interim Chair, said: “Alex is a great figure in British television. She has been one of the most impactful CEOs since Jeremy Isaacs’ founding of Channel 4 more than 42 years ago.

“She is business minded and has also been transformational both culturally and creatively, proving time and again her extraordinary ability to inspire and drive positive and meaningful change. Under her leadership, Channel 4 has moved with the times and driven the times.

“Her commitment to Channel 4’s public service mission has been unwavering. She has backed entertaining, shocking, interesting telly, never playing it safe and her grit and resilience more than met the rough-tough challenges of recent times.

“She leaves a strengthened and well-run Channel 4 that will continue to flourish, with its Fast Forward strategy reengineering the organisation for the future.

“While change is never easy, especially when so consequential, I could not be more pleased that Jonathan Allan, our excellent Chief Operating Officer, will serve as interim CEO while the Board focuses on a permanent replacement for Alex.”

Alex Mahon said: “Working at Channel 4 has been a lifetime privilege because Channel 4 is the most extraordinary organisation. What we get to do here is much more than television because we reflect our country with humour, creativity, grit, and care. We try our best to challenge convention and to change conversations. And we do it with a kind of irreverent brilliance that simply doesn’t exist anywhere else.

“I feel lucky beyond belief to have had the chance to lead Channel 4 for nearly eight years – through calm seas (very few) and stormy waters (more than our fair share). From navigating the threat of privatisation (twice), to shifting out of London, to digital transformation, lockdowns, political upheaval, advertising chaos – there has never been a dull moment. But through every twist and turn, there’s been one constant: the astonishing calibre, resilience, and creativity of all my colleagues at Channel 4.

“Together, I hope that we have evolved what Channel 4 means and what it stands for. We’ve protected the brand, even as we reinvented it. We’ve stayed risky, relevant and relentlessly new – with 60% of our shows fresh each year. And through it all, it’s been the programmes – and their impact – that have brought me the most joy and pride.

“Most recently, the Paralympics changed lives. It changed perceptions. And that really matters.

“And in the last few months our Gen Z work – giving voice to the experiences of a generation too often overlooked and spawning so many national conversations – is another example of why Channel 4 has to exist.

“Shaping the national conversation in ways no other broadcaster dares to. Doing things that are bigger than programmes. Not just public service – actual public impact.”