"President Bush has been incredibly supportive of his brother’s campaign and Governor Bush is excited to have him out on the trail," campaign spokeswoman Allie Brandenburger said in a statement.
His first appearance at a campaign event will come Monday in North Charleston, S.C.
Jeb Bush is hoping the former president's stature and popularity among conservatives in the South will give his campaign momentum in South Carolina and other upcoming Southern primaries.
The announcement comes a day after the campaign released a radio ad in which George W. Bush touted his brother as a "steady leader."
"We live in troubled times, with the military deployed around the world. We need a strong leader with experience, ideas and resolve," the former president says in the ad.
"There’s no doubt in my mind that Jeb Bush will be a great commander in chief for our military."