Pollsters at the Washington DC-based company noted how the US evangelist featured in their top ten lists a record 61 times - more than any other person
Publishing the new findings, they said: "The top ten list this year is notable for the absence of two men who often ranked high but who passed away in 2018, Senator John McCain and Rev Billy Graham."
Former US President Barack Obama topped Gallup's 2018 most admire men list, while incumbent US President Donald Trump and former leader George W Bush came second and third, respectively.
The pollsters continued: "Rev Graham was in the top ten every year from 1955 through 2017, with the exception of 1962. Graham never finished first, but he was second eight times, most recently in 1999."
Rev Graham died at his home in North Carolina in February 2018 - aged 99.
Gallup asked Americans earlier this month which living man and woman they most admired anywhere in the world. Pope Francis was voted the fourth-most admired man.
Former US First Lady Michelle Obama topped the females list, unseating Democrat politician Hillary Clinton from the number one spot for the first time in 17 years.
Queen Elizabeth II ranked fourth. Her Majesty has been placed in the top ten 50 times.
Gallup has published its annual most admired men and women rankings every year since 1946 - except 1976.
Stay up to date with the latest news stories from a Christian perspective. Sign up to our daily newsletter and receive more stories like this straight to your inbox every morning.