This is a sign that consumers are beginning to feel the squeeze amid a rise in inflation.
Sales were down 0.3% on the month, missing economists' expectations of a 0.9% increase and following a downwardly-revised 2.1% drop in December.
In the three months to January, sales were down 0.4% compared to the previous quarter, marking the first fall since December 2013.
On the year, retail sales rose 1.5%, undershooting expectations for a 3.4% jump. Meanwhile, sales excluding auto fuel declined 0.2% on the month and 2.6% on the year.
The report also showed that average store prices including fuel rose 1.9% compared with January 2016, which is the largest year-on-year price increase since July 2013.
ONS senior statistician Kate Davies said: "In the three months to January, retail sales saw the first signs of a fall in the underlying trend since December 2013.
"We have seen falls in month-on-month seasonally adjusted retail sales, both in conventional stores and online, and the evidence suggests that increased prices in fuel and food are significant factors in this slowdown." ■
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