Initial claims dropped by 23,000 to 264,000 in the week ending October 11, an eight percent decline from the previous week.
That is the lowest weekly number for jobless claims since April 15, 2000 when 259,000 people filed, and another sign of an improving jobs market.
Analysts expected last week's claims to rise slightly to 290,000.
The Labor Department gave no reason for the steeper-than-expected decline.
Jobless claims, a sign of the pace of layoffs, have now remained under 300,000 for five consecutive weeks, and the monthly average has fallen to 283,500, 4,250 fewer than the monthly average reported last week.
That also is the lowest level in 14 years, since the week of June 10, 2000, when the monthly average was 283,500.
A year ago last week, new claims numbered 355,000. From that point, the claims have fallen 25.6 percent over the past year.
The US unemployment rate has come down a point during that period, falling to 5.9 percent in September, the lowest level in six years.