The loveable rogue, who passed away in late 2010 after actor Bill Tarmey decided to leave the soap, beat off competition from Blanche Hunt, Steve McDonald, Hilda Ogden and Rita Sullivan to take the top spot.
Just one vote separated Jack and Blanche in the final results.
The poll has been carried out on the popular Coronation Street Blog fansite in recent months and the top 20 characters were as follows:
1. Jack Duckworth
2. Blanche Hunt
3. Steve McDonald
4. Hilda Ogden
5. Rita Sullivan
6. Roy Cropper
7. Becky McDonald
8. Graeme Proctor
9. Hayley Cropper
10. Betty Williams
11. Mike Baldwin
12. Fred Elliott
13. Bet Lynch
14. Audrey Roberts
15. Ena Sharples
16. Peter Barlow
17. Elsie Tanner
18. Norris Cole
19. Ken Barlow
20. Vera Duckworth
See the full top 60 and details of how the poll was put together here.
Llifon Jones, a contributor to the blog who organised the poll, told us: "I'm glad that Jack Duckworth has come on top because he is worthy of that prize. He was much loved for over 30 years and is a classic Corrie character.
"Blanche of course is another gem, played brilliantly by the late great Maggie Jones and worthy of second place. Then there's Steve McDonald who is a firm favourite and deserves to be third.
"It's wonderful that despite it being 25 years since she last appeared, Hilda Ogden still has a place in fans' hearts and occupies the fourth place. And Rita is soap royalty - Queen of the Kabin and Duchess of the Street and deserves to be ranked fifth. The top 20 symbolises, I think, the cream of Corrie."
Speaking of the wider results, he added: "For me, I was shocked to see Annie Walker having just scraped entry into the top 30, whereas I would've put her in the top 20 or top 10. Although it's been nearly 30 years since she last appeared, through YouTube you can watch classic Corrie and Annie ruling the roost at The Rovers so I did think she'd have ranked higher.
"Then there's Vera, Elsie and Ena who I thought would've been in the top 10. On the other hand, I was surprised to see Mike Baldwin ranked so high - I didn't think he was that popular. I was happy however that Rita made the top 5 because she's my favourite character!
"But looking at the top 20 I think they represent both sides of Corrie - the drama and humour that makes it unique and makes the other soaps look in awe. Side by side with the dramas of Elsie, Ken, Mike, Peter and Becky, you've got the hilarious antics of Hilda, Norris and the Duckies and the fabulous one-liners of Blanche and Betty.
"What this poll shows is as fans we love that mix of humour and drama and we don't need sensationalism to stay glued to our screens - we love it because, as Tony Warren said, it 'portrays the lives of ordinary folk'."
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