The former public schoolboy and presenter of the likes of Sale of the Century is of course the perfectly-spoken, cravat-wearing English gent – not someone you'd guess once sat on a doorless toilet stall in a Clydebank yard, worked in sheds with welders and wore overalls dirtier than the jokes which assaulted his gentle eardrums.
But Parsons, 90 in October and looking 20 years younger, reveals Glasgow was in fact the making of him.
When he was 16, he found himself ejected from his cosy Hampstead home by his parents, evicted to a city which at the time was known in the south of England for its slums, razor gangs and incomprehensible speech patterns.
Why? A wicked sense of humour – or an unusual set of parenting skills, even for the time?
"It was neither," says Nicholas, smiling, during a trip to Glasgow to promote the Aye Write Book Festival.
"My parents were loving. They thought they were doing it for the best."
How could that be so?
"They knew I wanted to become an actor, and my mother thought everybody in what she called 'the theatre' was a bit debased.
"I had a stutter and was dyslexic and I think she looked at me and thought that if someone like me went into theatre I would end up as an alcoholic – or pervert in the gutter."
The answer? Send young Nicholas off to North Britain, to a tough city in which the innate thespianism would be kicked right out of his very being.
Except that's not the way it worked out at all.
Yes, Nicholas was lined up with a five-year engineering apprenticeship amid the noise and grime of Clydebank's shipyards (the family had Scottish relatives whose friends owned Clydebank pump and turbine firm Drysdale's).
But Glasgow, surprisingly, was to prove his saviour.
"The next thing I knew an apprenticeship had been organised and I was on the train north," he recalls. "These friends met me at the station and took me to my digs at the YMCA in Sauchiehall Street. Then I was on my own."
Not quite. While living at the YMCA, Nicholas discovered the city was alive with culture, a thriving theatre town – and it didn't take long for the acting hopeful to find similar friends.
He soon joined Rutherglen Rep, home of comedy giant Molly Urquhart and later the Alhambra Rep, working in theatre at nights and the shipyard by day.
When radio talent spotter of the day Carroll Levis came to town, Nicholas, who had a great talent for impressions, auditioned, landed a spot on his London radio show and performed as Nick Parsons the Radio Deceiver.
His parents knew about the performance, but didn't come to see their son.
But it was the shipyard workers, the genuine no-nonsense characters who took him under their wing and became his greatest fans.
He reveals at first he was treated with suspicion, thanks to his posh accent. And the workers reckoned he was a boss's plant.
However, the young man who wore a beret on top of his shipyard overalls fitted in well with the bunnet-wearing boys of the yard, winning them over with a quick wit and a talent for impressions of the film stars of the day.
"The noise of the engines only stopped at lunchtime and the relief was indescribable," he recalls of work.
"We would hungrily devour our pieces with grimy hands.
"Only the offices had washing facilities, they also had the canteen. There was a marked division between those who wore jacket, collar and tie and those who wore a boilersuit."
Nicholas finished his apprenticeship, headed back to London and began a career in showbiz.
He appeared in films, on the West End stage and broke into television in the 50s playing the straight man to comedian Arthur Haynes and then in the late 60s with The Benny Hill Show from 1969 to 1974.
Eventually, his parents acccepted his determination to be a performer.
And he still works hard, fronting Radio Four's Just A Minute and will be appearing at the Edinbuirgh Festival Fringe with Nicholas Parson's Happy Hour.
But his heart still belongs to Glasgow.
"Other people in showbiz don't want to give credit to those who gave them a leg up, but I do," he says. "And it's the people of Glasgow to whom I feel so incredibly grateful."