Clarkson 'fessed up in a column in The Sun, saying that he and his Top Gear co-presenter were caught doing 141 and 143 km/h (88 and 89mph) respectively.
French police were not amused, and the pair were fined "everything [they] had in [their] wallets".
What's more, the gendarmes took away their driving licences, leaving the duo stranded and unable to drive the Aston Martin Vanquish and Porsche 911 GT3 that they had been travelling in up to that point.
"This wasn't the end of the world for us, because the film crew came to the rescue," said Clarkson, "but if you're travelling alone, you are properly stuffed.
"We subsequently learned that we would not be allowed to drive in France for three months."
Clarkson added that they had been on their way to film new sections of Top Gear's annual DVD.
He quipped that the ban "explains why, in the next series of Top Gear, you may notice we seem to be doing an awful lot of stuff in Italy."