Bush's favorability ratings also bested those of the Republican Party at large (41 percent favorable, 46 percent unfavorable) and Vice President Joe Biden (42 percent favorable, 45 percent unfavorable).
A wave of recent polls has shown Romney struggling to keep up with President Barack Obama. A lower favorability rating than Bush, who was recently named the most unpopular living U.S. president, shows how difficult it has been for the GOP nominee to resonate with voters during his current presidential bid.
Romney has avoided mentioning Bush's name while campaigning across the country, often referring to the former president only as Obama's "predecessor." Bush was also noticeably absent from the Republican National Convention in Tampa in August, but has stated his support of Romney.
"I'm interested in politics. I'm a supporter of Mitt Romney," he said in an interview in July. "I hope he does well. But you know, he can do well without me."