Jason Fox joined the Royal Marines Commandos in 1992 at the age of 16. In 2001 he joined the Special Boat Service and reached the rank of Sergeant. After 20 years of military service Fox was medically discharged in 2012 having, been diagnosed with Post Traumatic Stress Disorder (PTSD).
Fox is one of the original presenters and directing staff on SAS: Who Dares Wins, a reality television programme where contestants experience a gruelling training course loosely based on a condensed version of the special forces selection process. Fox stars alongside former special forces soldiers Ant Middleton, Matthew ‘Ollie' Ollerton, Mark ‘Billy' Billington, and Jay Morton. The programme first broadcast in 2015 is produced by Channel 4. In 2019 the first season of Celebrity SAS: Who Dares Wins aired which also stars Fox.
In 2018 Fox presented a 3 part docuseries Meet the Drug Lords: Inside the real Narcos. The series positioned Fox in his first investigative journalism role, spending time within drug cartels in Mexico, Columbia and Peru, meeting and talking to people living and working in those communities. Fox's interviews in the series included Popeye (Jhon Jairo Velásquez) – known as one of Pablo Escobars' hitmen in Columbia. In 2019 Fox presented a documentary The final mission: Foxy's war which saw him return to Afghanistan where he had served in the military.
In 2017, Fox co-authored a book SAS: Who Dares Wins: Leadership Secrets from the Special Forces, with his fellow TV presenters and Special Forces soldiers Anthony Middleton, Matthew "Ollie" Ollerton and Colin Maclachlan.
Fox released his own first book, Battle Scars in 2019 which explores his struggle with mental health after being medically discharged from his military career in 2012 having been diagnosed with PTSD. Battle Scars became a Sunday Times best-seller.
His second book Life Under Fire: How to Build Inner Strength and Thrive Under Pressure is due to be released in October 2020.
Fox became the host of a podcast Jason Fox Wild Tales in 2018, in conjunction with the Book of Man, with whom he is a regular columnist. In each episode Fox interviews people who have experienced a variety of adventures in their life, touching on their background, and the mental and physical challenges they have faced.