Recent surveys conducted by YouGov indicate that most Americans believe in the existence of extraterrestrial life — and a significant portion is convinced that aliens may have visited Earth in recent years. For many, however, such a contact would not be reason for celebration: a large share of respondents believes that a direct encounter could bring negative consequences for human civilization, including the introduction of new diseases, unintentional harm, or even hostile behavior.
According to the data, 56% of Americans believe that aliens definitely or probably exist. This percentage far surpasses the level of confidence in other legendary creatures, such as Bigfoot (28%), the Yeti (23%), the Loch Ness Monster (22%), and the Chupacabra (16%).
When political affiliation is taken into account, the study shows that Democrats (61%) and Independents (59%) are more inclined to believe in extraterrestrial life than Republicans (46%) — a pattern that does not hold when it comes to mythical beings like Bigfoot or the Yeti.
A majority of Americans believe that aliens exist
30% of Americans believe UFOs, or unidentified flying objects, are probably alien ships or life forms; 45% believe they have some other explanation. Democrats are more likely than Republicans to believe UFOs are probably alien in origin (34% vs. 26%).
Democrats are more likely than Republicans to say UFOs are probably alien
In September 2024, only 35% of Americans felt that sightings of unidentified flying objects were most likely rooted in natural or scientific causes.
Close to half of U.S. adults (47%) think that extraterrestrial beings have either definitely or probably set foot on Earth at some point in history. Democrats are more inclined than Republicans to believe aliens have visited our planet (51% vs. 41%).
Opinions are also split regarding more recent encounters. About 42% of Americans say aliens have definitely or probably visited Earth in the past few years, while 41% believe the opposite. Once again, Democrats show slightly higher levels of belief in recent alien visits than Republicans (45% vs. 39%).
Americans are split on whether aliens have visited Earth in recent years
About 16% of Americans believe humanity will definitely or probably make contact with alien life within the next 10 years. Looking further ahead, 29% expect contact within 50 years, 42% within 100 years, and 46% think it will happen within the next 200 years.
People who already believe extraterrestrials have visited Earth are far more optimistic about future contact. Among those convinced aliens have been here, 31% expect contact in the next 10 years, 53% within 50 years, 71% within 100 years, and 76% within 200 years.
By contrast, Americans who don’t think aliens have ever visited are much more skeptical. Only 2% think contact will happen in the next 10 years, 5% within 50 years, 16% within 100 years, and 20% believe contact is likely within 200 years.
16% of Americans believe we will make contact with alien life by 2035
n September 2024, Americans expressed relatively similar expectations about the timeline for potential contact with extraterrestrial life: 17% believe it will happen within 10 years, 32% within 50 years, 41% within 100 years, and 44% within 200 years.
When considering the impact of an alien visit, the public leans toward caution. Americans are roughly twice as likely to say such an event would have a negative effect (29%) on human civilization rather than a positive one (14%). Another 25% believe it would have neither impact.
Political views also play a role: Republicans (37%) are more likely than Democrats (26%) to expect negative consequences. Meanwhile, two-thirds of Independents (66%) either think an alien visit would be neither positive nor negative (28%) or say they are unsure (39%).
Twice as many Americans say an alien visit would have a negative effect on human civilization than a positive one
Americans who believe aliens have not visited Earth are nearly twice as likely as those who believe they have to say an alien visit would have a negative impact (43% vs. 22%).
Overall, 28% of Americans think that contact with extraterrestrial life would lead to a more united world, increasing global cooperation. A smaller portion believes it would make the world more divided, heightening conflict (22%), while 20% say it wouldn’t change much either way. Political differences also emerge: Democrats (36%) are more likely than Republicans (25%) to think an alien encounter would bring about greater global unity.
Democrats are more likely than Republicans to think alien encounters would make the world more united
Most Americans consider several outcomes fairly plausible if humanity were to encounter extraterrestrial life. A strong majority believes aliens would be far more technologically advanced than humans (74%), would prefer to remain hidden (66%), and might bring new diseases capable of infecting humans (55%).
Half of Americans (50%) think aliens would likely be able to communicate with us. Meanwhile, 43% say it’s likely aliens could unintentionally harm or kill people, and another 43% believe they would arrive peacefully.
Fewer Americans attribute lighter traits to extraterrestrial visitors: only 29% think aliens would have a sense of humor, while 28% say this is not very or not at all likely.
Majorities of Americans think if we encountered aliens, it’s likely they would be more technologically advanced than humans and want to stay hidden
About 73% of Americans — including 75% of Democrats and 72% of Republicans — believe that if the U.S. government had evidence of UFOs, it would keep that information hidden from the public. Only 13% think the government would actually reveal such evidence.
Roughly one in five Americans (21%) say they have personally seen something they believed was a UFO. People living in rural areas (28%) are more likely than those in other types of communities (19%) to report such sightings.
Americans who live in rural areas are more likely to say they have seen a UFO
Among Americans who say they have seen a UFO, 28% think it was more likely to be alien in nature and 48% think it’s more likely that it had some other explanation.
Methodology: This article includes results from an online survey conducted on November 4 – 9, 2025 among 1,114 U.S. adult citizens. Respondents were selected from YouGov’s opt-in panel to be representative of adult U.S. citizens. The sample was weighted according to gender, age, race, education, 2024 presidential vote, 2020 election turnout and presidential vote, baseline party identification, and current voter registration status. 2024 presidential vote, at time of weighting, was estimated to be 48% Harris and 50% Trump. Demographic weighting targets come from the 2019 American Community Survey. Baseline party identification is the respondent’s most recent answer given around November 8, 2024, and is weighted to the estimated distribution at that time (31% Democratic, 32% Republican). The margin of error for the overall sample is approximately 4 percentage points.
