Superior Court Judge John Doyle sentenced the 18-year-old actor to three years probation and ordered Osment to spend 60 hours in an alcohol rehabilitation and education program, as well as attend at least 26 Alcoholics Anonymous meetings over a six-month period.
Osment, who didn't attend the court hearing, also must pay $1,500 in fines.
The actor's attorney, David Wood, entered the no contest pleas on his client's behalf to one count each of misdemeanor driving under the influence and misdemeanor marijuana possession. Two other charges - another misdemeanor DUI and a vehicle code infraction - were dropped by prosecutors.
Messages left for Wood and Osment's publicist were not immediately returned Thursday.
Osment fractured a rib and injured his shoulder when he crashed and flipped his 1995 Saturn in La Canada Flintridge on July 20. No one else was in the car, which hit a mailbox mounted on a brick base.
Authorities said the actor's blood-alcohol level was measured after the accident at .16 percent, twice the legal limit.
Osment's movie credits include "The Sixth Sense," in which he was nominated for an Academy Award, and "Pay It Forward." He recently finished work on the film "Home of the Giants."