"I believe that as our next Governor, I can have a bigger impact addressing the unique challenges and opportunities we face in Louisiana," the senator said in an email obtained by The Associated Press from a member of Vitter's staff.
Vitter's announcement ends months of speculation about his intentions, and his decision is expected to influence which other potential candidates enter the race.
Gov. Bobby Jindal is term-limited, so the race is wide open. Vitter can run without forfeiting his current position in the U.S. Senate, which isn't up for re-election until 2016.
In a preview outline of his priorities if he becomes governor, Vitter said he'll push for excellence in education, budget stability, tax and spending reform and government accountability.
"This will be my last political job, elected or appointed, period. So my only agenda will be to do what's best for all Louisianians, from our best and brightest to our most vulnerable," he says in the email, which also announces Vitter's campaign website.