Merrimack County Sheriff Scott Hilliard will resign at the end of next month.
Hilliard was convicted in January of aggravated drunk driving
At the time of his conviction, Hilliard said he planned to stay on the job until his term as sheriff is up in December.
County commissioners said they lacked the authority to remove him from his elected position.
Governor Chris Sununu, who had made Hilliard a member of his judicial selection commission, called for Hilliard to resign last month.
In a press release, Hilliard said it was not an easy decision to step down and thanked people for supporting him through "difficult times."
Hilliard was sentenced to five days in the Belknap County House of Corrections, and will lose his driver’s license for up to 18 months.
Hilliard has appealed his conviction to the New Hampshire Supreme Court.