The funeral services of William's father Robert, killed at the North West 200 in 2008, and his uncle Joey, who died while racing in Estonia eight years earlier, took place at the same church.
Now motorsport fans are expected to descend on Garryduff to pay their respects to the third member of the Dunlop racing dynasty to lose their life to the sport.
William (32) was killed instantly while participating in the practice session of the Skerries 100 in Co Dublin last Saturday.
Rev Kirkpatrick, who officiated at both Joey and Robert's funerals, said his chaplaincy role within the sport meant that he had been confronted with a number of tragedies over the years, including those faced by the Dunlop family, whom he said were coping as best they could in the circumstances.
"They are a remarkably strong family," he said yesterday.
"People are just heartbroken. This young man at 32, with his whole life ahead him, who added so much to his family and partner, to his little girl.
"Many people I know around the world that I'm friendly with will be praying.
"And I believe that God will be there to help."
He added that his thoughts would be with William's pregnant partner Janine Brolly, who is due to give birth in September, their daughter Ella, who turns two on Sunday, and the racer's mother Louise and brothers Daniel and Michael.
Michael was also riding in the practice session that claimed William's life last weekend.
Rev Kirkpatrick (above) is minister of Portrush Presbyterian Church, but he ministered at Garryduff between 1987 and 1993.
He said that as the Dunlop family struggles to come to terms with the loss of William, the local community would be there for them at this extremely difficult time.
"Ballymoney has always owned its motorcyclists, its riders," he said, citing how the town had built memorials to Robert and Joey.
"I've no doubt that there is a community sense of grief."
Meanwhile, money to help William's family continued to pour in yesterday in memory of the talented rider.
At the time of going to press, over £15,000 in donations had been made to an online fundraising campaign established in his memory - reaching three-quarters of its £20,000 target.
Initially, the target was half of that amount, but such was the public response it was broken in less than 24 hours.
The fundraiser was launched by Adrian Fegan, a family friend, who said the Dunlops were "very thankful" for the support shown by well-wishers.
"It's a small token to help them," he added.
"The response has been very, very good."
The latest wave of public generosity came as William's devastated mother Louise welcomed road racing fans into her Ballymoney home yesterday evening, a gesture described as "selfless" and "brave" by well-wishers on Twitter.
The invitation was extended on her behalf by close family friend Liam Beckett, who said it would give the fans the opportunity to pay their respects.
And books of condolence at venues across the Causeway Coast and Glens council area have garnered hundreds of signatures in Ballymoney, Coleraine, Limavady and Ballycastle since they were officially opened on Monday by mayor Brenda Chivers.
"The entire borough has been left shocked and saddened with the tragic events that unfolded at the weekend," she said.
"William was a fantastic sporting legend and he will be remembered for his many achievements."
Meanwhile, prayers and messages of support from racing fans also continue to flood in for another one of motorsport's well-known figures, Sam Graham.
The Ballymoney man, who worked as a mechanic for Joey Dunlop during some of the racing legend's most successful years, is in a critical but stable condition in the Royal Victoria Hospital following a crash at the weekend.
Mr Graham was flown to hospital by air ambulance last Saturday evening after the motorcycle he was riding was involved in a three-vehicle collision in Co Antrim.
In a tragic coincidence, the collision took place at the same time William lost his life.