Scotland has a record number of billionaires with seven now among the richest people in the UK.
The number of billionaires living in Scotland or with substantial business interests north of the border has risen from six last year, according to The Sunday Times Super-Rich List.
Mr McColl, of engineering business Clyde Blowers, has an estimated fortune of £1billion.
The Grant-Gordon whisky family tops the Scottish element of list with a fortune of £1.9bn.
The Banffshire distillers ousted Mahdi Al-Tajir from the top spot in Scotland.
Mr Al-Tajir, whose interests include a develop-ment of luxury homes at Gleneagles, is worth £1.67bn according to the list.
Sir Brian Souter and Ann Gloag, the siblings who founded the Stagecoach transport empire, have joined the billionaire club for the first time. They share a fortune of £1bn - a rise of £270million on last year.
Other Scots on the super-rich list are Sir Ian Wood and family, whose £1.32bn fortune comes from oil services and fishing, and the Thomson family, owners of publisher DC Thomson, who are worth £1.2bn.
Former Harrods owner Mohamed Al-Fayed, who owns an estate in Scotland, is estimated to be worth £1.3bn.
Some 104 billionaires are now UK-based, more than three times the number a decade ago, and have a combined wealth of more than £301bn, according to the list.
It means Britain has more billionaires per head of population than any other country, while London's total of 72 sterling billionaires is more than any other city in the world, the study found.
Indian-born brothers Sri and Gopi Hinduja top the list of the UK's wealthiest billionaires with £11.9bn.
The richest Briton, the Duke of Westminster, is ranked 10th, with £8.5bn.