The luncheon will request donations of $25, $50 or $100 from attendees.
"This is a consequential time in our nation's history, and we need a strong leader," the former president wrote in a letter sent out to Bush supporters this week.
Previously, former president Bush had resisted direct involvement in his brother's campaign, for fear of hinting at a dynastic legacy of his unpopular presidency. Jeb Bush has had a difficult time highlighting his own aggressive foreign policy while simultaneously trying to distance himself from his brother's decision to launch the war in Iraq.
Jeb "My Own Man" Bush, on GWB fundraising letter: "I'm blessed to have a brother that loves me and wants to help me. Over and out."— Laura Ingraham (@IngrahamAngle) August 20, 2015
The luncheon will precede a larger fundraising retreat to be held in Houston in October, which will also feature the 43rd US president. His parents, former President George H.W. Bush and former First Lady Barbara Bush, will also take part in the retreat.
Other fundraising events could also be held in Arkansas in early October, according to a source speaking with the Washington Post.
Initially, the fundraiser was planned to take place on September 8, but it has now been scheduled for the 10th, placing George W. Bush in New York City one day before the 14th 9/11 since the terrorist attack on the World Trade Center.
He will not remain in the city, however, and will return to Dallas to commemorate that historic event.