He was the father of Crispian Sallis, who became a hugely successful set decorator and production designer on movies.
He was cast as Captain Striker in the Doctor Who (1963) episode Doctor Who: Enlightenment: Part One (1983), but industrial action at the BBC caused delays that forced him to relinquish the role, which was subsequently taken by Keith Barron.
He graduated from RADA and became an Associate Member of RADA.
He served in the Royal Air Force during World War II as a ground crew radio operator.
He was in attendance at the The 78th Annual Academy Awards (2006) ceremony with Nick Park and Helena Bonham Carter.
He was awarded the O.B.E. (Officer of the Order of the British Empire) in the 2007 Queen Elizabeth's Birthday Honors List for his services to drama.
He was the only actor to appear in all 295 episodes of Last of the Summer Wine (1973).
He did some dubbing work on the English soundtrack of Orson Welles' movie The Trial (1962), flying to Paris for a few days to do so. His agent told him he was unlikely to be paid anything for this, not even traveling expenses. Sallis replied that, on the contrary, he would be prepared to pay for the honor of working with Welles, whom he has always described as one of the two true geniuses he has worked with in his long career, the other being Nick Park.
He was diagnosed with macular degeneration in 1994.
He was considered for Dr. Armstrong and Sir Percy Heseltine in Lifeforce (1985).
He narrated a 1970 public information film advising householders to reduce the risk of burglary by locking all windows and points of entry.
He reconciled with his ex-wife, Elaine Usher, after their divorce. Although they eventually stopped living together, they remained on good terms. He also had a close relationship with his son.
For years he lived in a cottage on the banks of the Thames at Richmond, Surrey, until failing health and eyesight forced him to move to a flat in central London. His last years were spent at Denville Hall, the actors retirement home, in north London.
Ironically, he became best known for playing quintessentially northern English characters Norman Clegg in Last of the Summer Wine (1973) and Wallace in the Wallace and Gromit franchise despite actually hailing from Twickenham in Middlesex and having a natural accent of RP (Received Pronunciation).
He retired from acting after filming the final season of Last of the Summer Wine (1973) in 2009.
He chose to be buried in the graveyard of St John's Church, Holmfirth, Yorkshire - filming location for the long-running sitcom, Last of the Summer Wine (1973), in which he played "Clegg" - in the next grave to his friend and fellow Last of the Summer Wine (1973) actor, Bill Owen, who had died in 1999.
Son of Harry (1889-1964) and Dorothy Amea Frances (née Barnard) Sallis (1891-1975).