The TV presenter was criticised for comments he made about the Duchess in a newspaper column.
Jeremy Clarkson said he has apologised to Harry and Meghan over his column in The Sun newspaper in which he said he “hated” the Duchess of Sussex.
The TV presenter said he emailed the couple on Christmas Day to say his language in the column had been “disgraceful” and he was “profoundly sorry”.
Clarkson had previously said he “was horrified to have caused so much hurt”.
The Sun newspaper has also apologised for the December article.
In the column, Clarkson wrote that he lay in bed “dreaming of the day when she is made to parade naked through the streets of every town in Britain while the crowds chant ‘Shame!’ and throw lumps of excrement at her”.
He also claimed “everyone who’s my age thinks the same way”, and that her appeal you young people who “think she was a prisoner of Buckingham Palace” made him “despair”.
A record 20,000 complaints were made to press regulator Ipso after the piece was published.
In a lengthy Instagram post on Monday, the presenter of Amazon Prime’s The Grand Tour and Clarkson’s Farm and ITV’s Who Wants to be a Millionaire?, wrote: “Usually, I read what I’ve written to someone else before filing, but I was home alone on that fateful day, and in a hurry.
“So when I’d finished, I just pressed send. And then, when the column appeared the next day, the land mine exploded.
“It was a slow rumble to start with and I ignored it. But then the rumble got louder.
“So I picked up a copy of The Sun to see what all the fuss was about. We’ve all been there, I guess. In that precise moment when we suddenly realise we’ve completely messed up. You are sweaty and cold at the same time. And your head pounds. And you feel sick. I couldn’t believe what I was reading. Had I really said that? It was horrible.”