Stunned John Henderson, owner of Blantyre-based Henderson Travel, couldn't believe it when he received the penalty charge notice.
He was given the £60 fine, which is reduced to £30 if it is paid within 14 days, after a vehicle from his bus fleet drove on a city centre road designated for buses, taxis and cyclists only.
The number 329 bus was travelling from Stobhill Hospital to West Regent Street when one of Glasgow City Council's CCTV cameras snapped the registration plate on Cathedral Street.
The 27-seater Henderson-branded bus was 'caught' on February 5 at 7.42am.
Mr Henderson, 57, said he and his wife Linda were "speechless".
He said: "It is sheer stupidity that a bus can be fined for driving in a bus lane. This was a proper bus. It's a small to medium sized bus with 27 seats – but it's still a bus. It's an overzealous attack by the council."
As the Evening Times exclusively revealed last month, Cathedral Street is the second most prolific money-generating street in Glasgow as the council clamps down on the illegal use of bus lanes.
More than £500,000 in fines has been made after almost 20,000 motorists were caught driving in the bus lane between April 23 – when the council launched its CCTV crackdown on bus lanes – and December 31, last year.
It is second to Glassford Street bus lane which has netted around 28,000 drivers, letting the council rake in nearly £700,000 from fines.
Mr Henderson, who launched his company 30 years ago, accused council bosses of using the lanes as a way of raking in cash.
He said: "This has reinforced to me that bus lanes are one big money-making exercise.
"This has nothing to do with trying to keep traffic running smoothly, which is what bus lanes are meant for."
A Glasgow City Council spokesman said the fine was sent out in error. He said: "Another vehicle was in the lane behind the bus lane and it was included in the picture taken by the bus lane camera.
"A notice was sent out by mistake and it has now been cancelled."