Douglas has stood for Parliament five times, won four times, and helped win the EU referendum.
In April 2017, he announced he would not be standing at the next General Election, declaring his "job done". The only person Douglas ever lost an election to was Tony Blair, against whom he stood as the Conservative candidate for Sedgefield in 2001.
"One of the more remarkable - and effective - parliamentary careers of the 21st Century"
An optimist who believes that the world is getting better, Douglas is very concerned about what he sees as the emergence of a political and economic oligarchy. It is this, he argues, that is fueling the rise of destructive, radical populism.
Douglas has been at the forefront of the revolt against politics-as-usual. He won UKIP their only seat at the last General Election, and co-founded Vote Leave, the official campaign group that won the recent EU referendum.
Douglas' book, Rebel: how to overthrow the emerging oligarchy, was published by Head of Zeus in April 2017. His earlier book, The End of Politics and the Birth of iDemocracy, anticipated many of the changes that we are now seeing throughout the Western world.
"By any reasonable measure, Carswell has been one of the most influential backbenchers in recent memory. Possibly, even, the most influential of all"
Douglas has pioneered the use of data and digital technology to campaign and communicate. This helped him win the Clacton by-election in October 2014 with "the largest increase in the vote achieved by any party" in any British election ever. He has produced a campaign video that was watched by over 1.4 million people on Facebook.
Before politics, Douglas had a proper job working for a FTSE 100 fund manager.
He is married to Clementine, and is a dad. He loves gardens and growing things.
Born in 1971, Douglas' home was in Uganda until his late teens. He read history at the University of East Anglia and King's College, London.