He told the Times newspaper that he could easily have designed URLs not to have the forward slashes.
"There you go, it seemed like a good idea at the time," he said.
He admitted that when he devised the web, almost 30 years ago, he had no idea that the forward slashes in every web address would cause "so much hassle".
His light-hearted apology even had a green angle as he accepted that having to add // to every address had wasted time, printing and paper.
Sir Tim is currently director of the World Wide Web Consortium and he is also working with the UK government to help open up access to government data.