The other two-thirds of the public consider their primary news sources trustworthy, mainly print news and broadcast television, according to the report from California-based non-profit RAND Corporation.
"A lack of time and competing demands may explain why a third of Americans turn to news sources they deem less reliable, which suggests improving the quality of news content or teaching people how to 'better consume' news isn't enough to address 'Truth Decay,'" said Jennifer Kavanagh, senior political scientist and co-author of the report.
"Media companies and other news providers may need to provide more easily accessible and digestible ways for individuals to consume high quality investigative journalism".
"Truth Decay" is a phenomenon defined as diminishing reliance on facts, data and analysis in public life.
The report draws from a national survey of 2,543 Americans to examine how reliability, demographics and political partisanship factor into news choices and how often people seek out differing viewpoints in the news.
About 44 per cent of respondents reported that news is as reliable now as in the past, while 41 per cent said it has become less reliable and 15 per cent - mostly women, racial and ethnic minorities and those without college degrees - said it is more reliable.
Respondents who lean on print and broadcast platforms were more likely to deem them reliable.
Those who rely on social media and peers for news, on the other hand, don't see those platforms as reliable yet still choose to get their news from these sources.
"The findings suggest that perceived reliability is not the only factor that drives what Americans choose as their go-to news sources," said Michael Pollard, a sociologist and lead author of the report.
"Despite acknowledging that there are more reliable sources for news, people with demands on their time may be limited to using less reliable platforms."
Asked whether they ever seek out alternate viewpoints when catching up on the news, 54 per cent said they "sometimes" do, 20 percent said, "always or almost always," 17 per cent said "infrequently," and 9 percent said, "never or almost never."
The report also identified the four most common combinations of news media types consumed by Americans: print publications and broadcast television, online, radio, and social media and peers.
Those who are college-educated were less likely to get their news from social media and peers, instead opting for radio and online sources.
Those with less than a college education were more likely to report "never or almost never" seeking out news with alternate viewpoints.
"Those who are married were three times more likely than singles to rate their peers as the most reliable source for news," said the report.
Unmarried people were more likely than married people to report they "always or almost always" seek out sources with differing views.
( With inputs from IANS )