The Index of Consumer Sentiment hit 87.9 in October, according to the University of Michigan on Friday, hitting its lowest since Sept. 2015.
Economists expected the index to hit 92 in October, up from 89.8 in September's final reading, according to Thomson Reuters consensus estimates.
The October loss was concentrated among households with incomes below $75,000, whose index fell to its lowest level since Aug. 2014, according to the report.
The report said it is likely the uncertainty around the upcoming presidential election negatively influenced consumers, especially those with lower income.
"Prospects for renewed gains, other than a relief rally following the election results, would require somewhat larger wage increases and continued job growth as well as the maintenance of low inflation," said Richard Curtin, the surveys of consumers chief economist, in a press release.
The monthly survey of 500 consumers measures attitudes toward topics like personal finances, inflation, unemployment, government policies and interest rates.
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— CNBC's Mariam Amini contributed to this report.