Sources close to the star said he died from a heart attack this morning while holidaying in the south of France.
The legendary comedian, TV and stage actor appeared on Emmerdale, Heartbeat and Last Of The Summer Wine, while also wowed audiences for years performing in pantomimes across South Yorkshire.
More recently he is best known for playing Eddie Dawson on the hit ITV show Benidorm and many of his co-stars spoke of working with a 'wonderful and lovely' man.
Benidorm writer Derren Litten tweeted: "Very sad Benidorm news guys. The wonderful Bobby Knutt has passed away suddenly aged 71. Love to his family."
Co-star Tony Maudsley added: "Take a bow Grandad Dawson. Your Benidorm family will miss you."
Fellow Benidorm actor Jake Canuso described him as a "lovely man" who will be "dearly missed."
Actress Stephanie Dooley Day performed in panto alongside Bobby and posted on Twitter: "So sad to hear the lovely Bobby Knutt has passed away, treasured memories of our panto days. RIP Lovely man."
Singer and musician Jonathan Mark said: "Devastated to hear the passing of comedian and good friend Bobby Knutt. Very fond memories of our times together."
Comedy band The Grumbleweeds, who performed on numerous occasions alongside Bobby, described him as a "great friend and a funny, funny man."
Tailor to the stars Neil Crossland made all of Bobby's stage outfits and had known him since he was a teenager.
He said: "It's really sad news. I have heard he died in France where he was on holiday with his new girlfriend.
"He was really enjoying life to the full. He was doing really well on TV's Benidrom and he was still doing what he did best - making people laugh.
"They don't make them like him anymore. He was one of the last great comedians of his generation. His death has come as a real shock to us."
Author Neil Anderson was one of the last people to interview Bobby for his latest book 'Dirty Stop Out’s Guide to Working Men’s Clubs' and told how the comic was due to attend the launch night as part of the Off the Shelf festival next month.
He said: "He was larger than life and in great spirits when I spoke to him.
"He was a great comedian in his day and he really enjoyed telling me about his days on the working men's club circuit.
"He was still so full of life, it's a great loss. The launch night for the book will now be a tribute to him."
Born in Sheffield in 1945, Bobby attended Abbeydale Grammar School before embarking on a successful showbiz career.
The comedian had regular roles in Sheffield pantomimes, performing at the Crucible and Lyceum theatres.
Knutt was perhaps best known for playing Albert Dingle in Emmerdale between 1995 and 2004.
He was married to Donna Hartley, once hailed the 'golden girl' of British athletics, before passing away suddenly in June 2013, aged 58.
Friends said Bobby was last living in Elsecar, Barnsley.