Miller covered the course at Bormio in 2 minutes, 57 tenths of a second Saturday to edge Austrian Andreas Buder and Jan Hudec of Canada.
The U.S. Ski Association said the win was the 26th World Cup victory of Miller's career. The U.S. record is 27 set by Phil Mahre.
Miller said after the race that he tends to ski better on the more-challenging courses such as Bormio, which is noted for its long 3.3 kilometer distance. The same course will host the World Cup finals in March.
The current season standings have Benjamin Raich of Austria on top with 524 points and Didier Cuche of Switzerland second with 503. Miller is third with 406.