Donovan, a Democrat, was first elected attorney general in 2016. He previously served as the state’s attorney in Chittenden County.
“It has been an honor and a privilege to serve the people of Vermont for nearly the last 16 years as an elected official,” he said in a statement, adding that the attorney general’s office “has a strong team in place to carry out its duties to protect Vermonters” until the next attorney general is sworn in.