On this day in 2011, the iconic midfielder took his own life, aged 42 while manager of Wales, sending shockwaves through the football world.
Having made an astonishing 840 domestic appearances, Speed was one of the most loved football figures in Britain, and many struggled to come to terms with the shocking nature of his death.
In the decade which followed, Speed's suicide sparked a more open and honest conversation about mental health in sport.
And today, we can remember a monumental force of the modern football era.
Former Premier League striker Dean Ashton reflects on his memories of the ex-Leeds, Everton, Newcastle, Bolton and Sheffield United midfielder, comparing his heading ability to Manchester United icon Cristiano Ronaldo.
He told talkSPORT: "You only have to listen to some of the comments and how he affected so many people. What an incredible man he was.
"To watch him play as I grew up, I've never seen anyone leap so high and be so aggressive when they headed the ball.
"It was a joy to watch. We talk about Ronaldo's leap. Speed had one of those. He just hung there and headed it in.
"He led by example with that big smile that he had. It's such a sad, sad thing to have happened. But rightly so, we remember all the great things about Gary Speed."
Meanwhile, Arsenal legend Ray Parlour hails both the player and the man, revealing he still has one of Speed's shirts - which he hopes to one day pass on to the late player's two sons.
Parlour told talkSPORT: "Gary was a superb player, you ask any club he was at, especially at Leeds United when I played against him.
"He was box-to-box, he scored some great goals, he was brilliant in the air.
"But more than that, Gary was always a great lad. He was a good looking boy, he was a proper poster boy, and he was such a great character as well.
"I was lucky enough to swap shirts with him in the 1998 FA Cup final when he was playing for Newcastle, it was an honour to play against him.
"I've still got the shirt, I've always said his boys can have that. Hopefully he did keep one and give it to his boys from the FA Cup final. I know he was on the losing side that day, but it's from a Cup final so it's so very important to you as a player.
"So I think one day I will be giving it back to his sons as a memory to their dad.
"Gary had a great, great career and it was sad to see him lose his life."