The one millionth update has taken just seven months to appear, and the Map Share community has signed up more than half a million users since launching in July 2007.
Harold Goddijn, chief executive at TomTom, claimed that the Map Share technology ensures that drivers always have the most accurate and up-to-date maps.
"We are very pleased to see that the TomTom Map Share service is used so intensely by our user community," he said.
"Road networks change every day, and often unexpectedly, but now users can improve their own maps easily and instantly directly on their device."
About two-thirds of the one million uploaded map improvements can be fixed instantly, while the remainder are forwarded to the TomTom development team.
TomTom Map Share is a proprietary map improvement technology available in 30 countries over five continents.
It is free to use on a range of TomTom devices, including the GO x20, GO x10, GO 700, GO 500, ONE XL and ONE.