Wilson, 37, and from Sheffield, was struck by flying debris and suffered head injuries during the Pocono IndyCar 500 race in Pennsylvania on 23 August.
About 500 people attended the seven-time IndyCar race winner's funeral at Paulerspury in Northamptonshire.
The family, friends and colleagues joined Wilson's widow Julia at Silverstone afterwards.
Ex-Formula 1 driver Mark Webber and retired IndyCar racer Dario Franchitti were among the pallbearers.
Webber said: "It was an honour for me to do that for the family because we are a family in many ways when it comes to motorsport.
"We know the dangers are always there. Motorsport has had good and bad patches when it comes to these tragic events and when it is really close to home then it hits you even harder.
"You think of the family and everyone who is going to be affected by this. Motorsport is a tight-knit family and when we need to get together in really tough times we do our best."
Jonathan Palmer, the former F1 driver who took Wilson on as a protÃ©gÃ©, and former F1 champion Sir Jackie Stewart also attended.
Palmer, who read an 11-minute eulogy in his honour, said: "Justin was the innocent victim in a cruel twist of fate when he was hit by flying debris from an incident ahead. It still feels like a bad dream but tragically it is only too real."
The father of two died a day after Sage Karam's car spun and crashed in front of him on lap 179 of 200.
Wilson's major motorsport breakthrough came in F1.
He won the Formula 3000 series in 2001, and two years later raised Â£1.2m to finance his F1 entry after setting up a company in his own name.
Wilson scored his only point from 16 races with Minardi and Jaguar during 2003 at the United States Grand Prix.
He moved to the US in 2004 and enjoyed greater success in Champ Car, finishing as series runner-up in 2006 and 2007 before switching to IndyCar racing in 2008, after Champ Car merged with the Indy Racing League.
He finished second in the previous IndyCar race in Mid-Ohio on 2 August, his first podium finish since 2013, while his final victory came at the Firestone 550 at Texas Motor Speedway in June 2012.
Mark Miles, chief executive of IndyCar parent company Hulman & Co, paid tribute to Wilson's "elite ability" and his "unwavering kindness, character and humility".

Zack Davies, 26, tried to kill dentist Dr Sarandev Bhambra, 25, in revenge for the murder of Fusilier Lee Rigby.
The racially motivated attack happened in Tesco in Mold in January and earlier this month Davies was jailed for life.
Speaking for the first time since the attack, Peter Fuller, 44, said it was "like something out of a horror movie".
"I will think about what happened for the rest of my life," he said.
"That's the image I still have in my head every night - him running towards me with the machete raised and dripping blood.
"It is like something out of a horror movie."
Mr Fuller spoke out about the ordeal before accepting an award for outstanding bravery from the Pride of Britain Awards.
Mr Fuller said he heard Davies shout "remember Lee Rigby".
"Initially I just thought it was kids larking about but then as I moved about four paces I saw a man on the floor surrounded by blood and the guy standing over him and hitting with a hammer," he said.
"I decided then that there was no way I was backing away.
"There was no-one else around me, they were all running and screaming, so I moved to one side to let Mr Bhambra run past and then I moved into the middle of the aisle and made myself as big as possible.
"I started shouting at the guy that what he was doing was madness and that I was ex-Forces. I made it clear that he was either going to have to go through me or he was going to stop."
During the trial, Gareth Preston, senior prosecutor for the Crown Prosecution Service Wales, said: "Such was the level of violence involved that, were it not for the extremely courageous actions of ex-serviceman Peter Fuller, this offence could have become an act of murder."
Mr Fuller will be honoured at the Daily Mirror's Pride of Britain ceremony at London's Grosvenor House on Monday night.
The funeral has taken place of British IndyCar driver Justin Wilson, who died during a race last month in America.
[NEXT_CONCEPT]
An ex-soldier who stopped a neo-Nazi beheading a Flintshire shopper with a hammer and a machete says he is still haunted by the savage attack.