This is the first year Trump has risen to the top spot in the annual survey and the 12th year for Obama. Each was named by 18 percent of respondents to the open-ended survey conducted Dec. 2-15.
Obama tied former President Dwight Eisenhower for the most times named as most admired man since the survey began in 1948.
The survey reflected the political divide in the nation, with 41 percent of Democrats naming Obama and 45 percent of Republicans naming Trump. The results also reflect Trump's rise in popularity, with a 45 percent job approval rating up from 40 percent in 2018 and 36 percent in 2017, Gallup noted.
The incumbent president has taken the top spot in 58 of the 72 prior Gallup polls.
Other men in the Top 10 this year were former President Jimmy Carter, businessman Elon Musk, Microsoft founder Bill Gates, Pope Francis, Vermont Sen. Bernie Sanders, California Rep. Adam Schiff, the Dalai Lama and investor Warren Buffett, though none earned mentions from more than 2 percent of respondents.
Former first lady Michelle Obama was named as the most admired woman for the second year, with 10 percent of respondents naming her, down from 15 percent last year. First lady Melania Trump came in second at 5 percent.
Among women, talk show host Oprah Winfrey, former Secretary of State Hillary Clinton and teen climate change activist Greta Thunberg tied with mentions from 3 percent of respondents, followed by Queen Elizabeth II, House Speaker Nancy Pelosi, Supreme Court Justice Ruth Bader Ginsburg, Massachusetts Sen. Elizabeth Warren, German Chancellor Angela Merkel and former U.S. Ambassador to the United Nations Nikki Haley.