The legendary comedian, TV and stage actor, who was born in Sheffield, appeared on Emmerdale, Heartbeat and Last Of The Summer Wine.
Knutt was married to Donna Hartley, once hailed the 'golden girl' of British athletics, before she passed away suddenly in June 2013, aged 58.
The actor played Albert Dingle on ITV soap Emmerdale and has had regular roles in 14 pantomimes in Sheffield.
Knutt most recently performed as Eddie Dawson in the hit British sitcom Benidorm.
Tributes are beginning to pour in for the much-loved actor on Twitter, including from Benidorm writer Derren Litten.