His lust for life, and will to make the most of his time on earth, inspired millions who heard his story.
And now, the speech he made to 4,000 people about living life to the full has come to light - and it's incredible.
In it, Stephen urges the audience not to do what he did - i.e. wait for something terrible to happen before they appreciate their own lives.
'It’s a bit of a shame that I’ve had to rely on tragedy, i.e. in the form of cancer, to remind me to have a good time, to remind me to do something'
'What I want you to think about is that in a way it’s a bit of a shame that I’ve had to rely on tragedy, i.e. in the form of cancer, to remind me to have a good time, to remind me to do something – you know, it shouldn’t be like that if we want to go out there and achieve stuff, we should go do that, you know. Life is for living' he says.
'See people like yourselves – you guys have got all the time in the world to make a difference to yourselves, to make a difference to all this, but what you might not have is the motivation to do that. Well you can’t give me your time to make me live longer, but what I can try and do is to give you a bit of my motivation you know, to go out there and achieve something, to go out there and help others, to go out there and enjoy life. I’m going to say once more, to make a difference. And that’s it,' he concludes.
After his death on Wednesday morning, Stephen's fundraising page was flooded with thousands of people wanting to give money to the Teenage Cancer Trust in his honour. His efforts have so far raised £3,651,000 for the charity.
Watch the full speech here: