Neeson, 48, was riding his 1989 Harley Davidson motorcycle around noon when a deer jumped into the road, according to the Dutchess County Sheriff's Office.
Neeson, who was wearing his helmet, was thrown from the motorcycle just before it ran into a tree about 70 miles north of New York City.
The Oscar-nominated Irish actor suffered a fractured right pelvis, a chipped left pelvis, and multiple leg abrasions. He was taken to a Connecticut hospital.
"I'm told that he's in good condition and that he's resting comfortably," said Alan Nierob, Neeson's publicist. "We're expecting a quick recovery."
Herman Staats of Hyde Park was driving his truck when he spotted Neeson lying on the roadside.
"He managed to crawl his way up back to the road," Staats said. "He wanted me to drive him back to his house right up the road, but I could tell his hips were bothering him."
Neeson was nominated for an Academy Award for his portrayal of Oskar Schindler in the 1993 epic Schindler's List. He has starred in Stars Wars Episode One: The Phantom Menace and Rob Roy.
Neeson married actress Natasha Richardson in 1994.
Sheriff's deputies said the deer died shortly after the accident.