The Manchester-born actor passed away at his holiday home in Tenerife on 9 November, aged 71.
On Tuesday, 700 people packed into the Albion United Reformed Church in Ashton-under-Lyne for his funeral service.
Members of the Corrie cast, past and present, joined Bill's wife Ali and their two children, Carl and Sara, to say a final goodbye.
Liz Dawn, best known as Bill's onscreen wife Vera Duckworth, was among the mourners - as was Nigel Pivaro, who played their onscreen bad-boy son Terry and also gave one of the eulogies.
"Behind the character was the man. Bill's huge generosity of spirit, his warmth, his wit, his patience, his wisdom," Nigel said.
"I think those qualities that he had in abundance we will keep them in our hearts as his legacy. They will stay with us forever more. That will be his lasting legacy. That is why he will live on in our hearts.
"Today the world is a little poorer for not having him with us and heaven is a little richer."
Alan Halsall and Kevin Kennedy, whose respective characters Tyrone Dobbs and Curly Watts both looked up to Jack Duckworth as a father figure, also attended.
Other Corrie favourites included William Roache (Ken Barlow), Julie Goodyear (Bet Lynch), Roy Barraclough (Alec Gilroy), Sally Dynevor (Sally Webster), Michael Le Vell (Kevin Webster), Brooke Vincent (Sophie Webster), Sue Nicholls (Audrey Roberts), Helen Worth (Gail Platt), Shobna Gulati (Sunita Alahan), Kate Ford (Tracy Barlow), and Jennie McAlpine (Fiz Stape).
On behalf of everyone who works at Coronation Street and has worked on the programme during its 52 years, and the loyal viewers - Bill, we salute you.
Samia Ghadie (Maria Connor)
As well as Nigel Pivaro, actress Samia Ghadie - who plays Maria Connor - also gave a eulogy.
Battling tears throughout, she described Bill as "one of the most decent and honourable men" you could ever meet.
"Jack and Vera were a truly unforgettable and formidable partnership, and I doubt we'll ever see that again," Samia said.
"They were simply iconic and Jack Duckworth will forever be a true Coronation Street legend."
She added: "And thank you, Bill, for being the light in our lives for all those years and for bringing so much joy and happiness to millions of people.
"We love you, we already miss you and we'll never, ever forget you."
In the order of service for William Cleworth-Piddington, Bill's real name, his family said: "Ali and all Bill's family would like to thank you for your attendance today and for the overwhelming messages of comfort and support they have received during this difficult time."
The service was relayed to allow hundreds of fans outside to hear it through the loudspeakers.
Bill joined the soap back in 1977 and served 31 years before finally calling time on his Corrie career.