(Read more: How cutting benefits will affect the jobless rate)
Overall, professional and businesses services again led the way with 170,000 new jobs, down a shade from November's 182,000.
The big number could sway economists to change their view of the monthly unemployment report from the Bureau of Labor Statistics, which is expected to show 196,000 additional positions, all but 1,000 from the private sector.
Deutsche Bank quickly reacted, with Joe LaVorgna, the firm's chief U.S. economist, tweeting that he was raising his forecast.
Moreover, the ADP report helps justify the Federal Reserve's gradual move away from its $85 billion a month bond-buying program known as quantitative easing. The U.S. central bank's Open Markets Committee voted last month to cut the program by $10 billion a month. FOMC minutes to be released later Wednesday should shed more light on the Fed's decision-making process and how big a role employment improvements have played.
The jobs numbers also refuted the notion that the snowy and cold December might depress job creation.
"There were some concerns we heard ahead of today's blowout ADP number that cold weather may have thwarted hiring in December," Andrew Wilkinson, chief market strategist at Interactive Brokers, said in a note. "Perhaps that's a story for January as record low temperatures disrupt the economy."
(Read more: Unemployment aid: What's at stake for the US economy)
Small businesses drove December's gains, adding 108,000 positions. Large businesses provided 71,000 jobs while medium-sized firms generated 59,000.
In industries, professional business services added 53,000 while trade, transportation and utilities generated 47,000 and manufacturing grew 19,000.
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—By CNBC's Jeff Cox. Follow him on Twitter