The appointment of Alfred Landry to a seven-year term has been approved by the legislature.
Landry, who served on the Court of Queen's Bench, was born in Robichaud in 1936 and became a lawyer in 1964.
He replaces Patrick Ryan, another former judge who had been commissioner since 2005.
In February, Ryan ruled that former Liberal premier Shawn Graham broke provincial rules because of his involvement in a government decision to give financial help to a construction company.
He said Graham was in a conflict of interest in 2009 when the Liberal government gave a $50 million loan guarantee to Miramichi-based Atcon.