The short list - if there is one - is believed to include Ohio Rep. Rob Portman, former Minnesota Gov. Tim Pawlenty and Wisconsin Rep. Paul Ryan.
In a statement issued Friday night, the Romney campaign said the running mate would be revealed at 9 a.m. EDT at the Nauticus Museum. Romney is kicking off a four-day bus tour through swing states.
Romney's choice comes as he tries to repair an image damaged by negative Democratic advertising and shift the trajectory of a campaign that's seen him lose ground to President Barack Obama.
The vice presidential selection will dominate headlines, and Romney's team has been relentlessly teasing the announcement for weeks.