The service took place at Christ Church, Hackenthorpe on Monday, May 24 and a line of veterans stood with military standards in tribute as the cortege arrived.
Men stood to attention and saluted the coffin, which was draped with a Union flag and topped with flowers and his medals on a cushion.
Douglas, aged 98, from Intake was one of the first troops to land on Sword Beach at 7.20am on June 6, 1944 when Allied troops began their push to finally secure victory in mainland Europe.
Their job was to clear the way for the invasion forces.
He served as an infantryman with 2nd Battalion East Yorks Regiment and braved extensive enemy gunfire on landing, which kept the troops boxed in for a time before they were able to advance.
Douglas also pulled a badly-injured comrade, Corporal Wilkinson, to safety but medics were unable to save him.
He served in France and Palestine, winning France’s highest military medal, the Legion D’Honneur.
After he returned to Normandy in 2019 for the 75th anniversary of the D Day landings, Douglas described what he saw as he left the ramp of the landing craft.
“I dashed out, and I could see the machine gun bullets hitting the sand about 10 yards in front of me.”
He remembered: “Our division was hand-picked to do the assault, we were the first ashore.
“It was just pot luck who was going to get there first. Our objective was to make the place clear for all the thousands of troops to follow, and that's what we did. We had heavy casualties."
He added: “It was really rough. We were boxed in for quite a while. But it had to be successful, and it was.
“If it hadn’t, it would've been a catastrophe. It was the worst part of the war, it was in such a small area.”
He concluded: “I think war is futile, there’s no doubt about that. There are no winners, there can't be.”
Douglas, who lost his wife Mary, aged 90, in 2019, leaves sons John and Stuart, five grandchildren and two great-grandchildren.
1. The funeral of D-Day veteran Douglas Parker at Christ Church Hackenthorpe. Picture: Chris Etchells
Douglas Parker's Union flag-draped coffin passes the honour guard on its way into the church Photo: Chris Etchells
2. The funeral of D-Day veteran Douglas Parker at Christ Church Hackenthorpe. Picture: Chris Etchells
A line of military standard bearers ready to honour D Day landings veteran Douglas Parker at his funeral, which took place at Christ Church, Hackenthorpe Photo: Chris Etchells
3. The funeral of D-Day veteran Douglas Parker at Christ Church Hackenthorpe. Picture: Chris Etchells
A salute for a fallen comrade Photo: Chris Etchells
4. The funeral of D-Day veteran Douglas Parker at Christ Church Hackenthorpe. Picture: Chris Etchells
The funeral cortege for D-Day veteran Douglas Parker at Christ Church, Hackenthorpe Photo: Chris Etchells