William Walter "Bill" Mercer (born 1964) is an American attorney and politician serving as a member of the Montana House of Representatives from the 46th district.

[2] Mercer was nominated by President George W. Bush as Associate Attorney General and served in the position in an acting capacity, but resigned before his confirmation hearing could take place.

[1][4] From 1994 to April 2001, Mercer served as an Assistant United States Attorney for the District of Montana.

On April 20, 2001, he was nominated by President George W. Bush to serve as the United States Attorney for the District of Montana.

[7] The project continues to coordinate with local, state, tribal, and non-governmental agencies and organizations to protect the safety and well-being of American children.