Tower Bridge was cordoned off at around midday on Friday while police investigated reports of a "suspicious package."
A City of London police spokesman told the Standard the road was closed to traffic and pedestrians as a precaution while officers looked into the incident.
The force earlier tweeted that people should find alternative routes.
Around an hour later, Met Police issued a statement confirming the bridge had reopened.
They tweeted: "Police attended Tower Bridge at 12:18hrs to reports of a possible suspicious package.
"The bridge was closed while the package was examined and was found to be non suspicious. The bridge has now re-opened."
Witnesses shared footage on social media of the landmark taped off with several police vehicles at the scene.
A number of Twitter users expressed relief that the incident was not terror related, with one earlier commenting: "Please don’t let there be a terrorist attack in the midst of a global pandemic."
