His opponent, Democratic nominee Joe Biden, would get about 45 per cent, according to the survey by the Bertelsmann Stiftung foundation.
Some 38 per cent of European Union citizens would not vote for either candidate, if they were voting this year.
When broken down by individual country the results varied - Poland is the only country where Trump was ahead of Biden, with the President polling at 38 per cent, compared to his challenger's 30 per cent.
Poles want a close relationship to the US for historical reasons, according to the study author Isabell Hoffmann. Some 77 per cent said that democracy in the US functions well, the DPA news agency reported.
By contrast, 51 per cent of people surveyed across Europe said they believe there has been a failure of democracy in the US.
But America still ranks well ahead of China as an important partner, according to survey respondents.
"Four years of Trump's government have left their mark on EU citizens. They acknowledge the importance of the transatlantic relationship, but are blunt in their assessment of what holds it together," Hoffman said.
The survey authors questioned 13,808 people in all EU states in September.