Roddy Dunlop KC, dean of the Faculty of Advocates, said he would "just like to pay the same tax as everyone else".
It comes after UK Chancellor Kwasi Kwarteng announced the scrapping of the top rate of income tax for those earning £150,000 a year or more, as well as a cut in the basic rate to 19p in the pound.
The measures do not apply in Scotland, where control over income tax rates and bands is devolved.
If the Scottish Government does not follow suit, everyone earning more than £14,732 will pay more income tax in Scotland compared to the rest of the UK.
Someone on £30,000 would pay £195.80 more next year, while those on £50,000 would pay £1,863.40 more.
High earners in Scotland would pay an additional rate of 46 per cent on earnings of more than £150,000, while those in the rest of the UK would pay 40 per cent.
This means someone earning £200,000 would pay £6,045.80 more.
Mr Dunlop tweeted: "I’ve lived in Scotland all my days. I love this place. I do not want to leave. But if there is this level of tax difference, I’d have to consider it. Northumberland is nice, apparently."
He described a tax gap of 6 per cent as "madness" and said it would put off higher earners from moving to Scotland.
Mr Dunlop added: "Why would they, when even those properly devoted to the country are considering their options?"
After his comments sparked a row on Twitter, Mr Dunlop clarified: "Look: I’m going nowhere. I’d just like to pay the same tax as everyone else. If that makes me greedy, fair enough."
Douglas McWilliams, a leading economist and deputy chairman of the Centre for Economics and Business Research, told The Sunday Times that “it would be realistic to assume about 20 per cent of top-rate taxpayers could move south” as a result of the changes announced by the UK Government.
Nicola Sturgeon has indicated she will not replicate the tax cut for the highest earners.