Williams pleaded guilty Friday to a misdemeanor count of driving while intoxicated in the Jan. 5 wreck and was immediately sentenced to a year in jail.
Prosecutors say the former New Jersey Net had a blood-alcohol level more than twice the legal limit.
The wreck happened the week before he pleaded guilty to aggravated assault for accidentally shooting and killing a limo driver in New Jersey.
The 42-year-old Williams will serve his one-year term after serving a five-year prison term in New Jersey on a separate assault conviction.
Williams retired from basketball in 2000 after nine seasons with the Nets and the Philadelphia 76ers.