Jones administered the oath of office in place of a judge on Thursday for his longtime friend and neighbor Adrian "Butch" Anderson, the sheriff in Dutchess County, N.Y., where Jones lives.
At the Poughkeepsie ceremony, which was attended by some 250 people, Jones said that his many movie roles included playing a judge in "Sommersby," a 1993 post-Civil War film that starred Richard Gere and Jodie Foster.
Jones provided the voice for the Darth Vader character in the original "Star Wars" trilogy. His deep, distinctive voice also was featured in Disney's animated film, "The Lion King."
The Associated Press contributed to this report.