The UK capital managed to beat numerous cities, including Edinburgh and Manchester, to stage the elite race's Grand Depart, but Johnson has claimed that spending £35m on doing so would not be hugely beneficial to London.
"I will not waste cycling money on something that would only deliver very brief benefits," Johnson told BBC London 94.9.
"I'm afraid I have got to put my hands up here and say I took the decision not to go forward with it. You've got to take some tough decisions in government and I think 35m quid on a one-off event was just not worth it for London."
London hosted the end of the third stage last year.