James Howard McGrath (November 28, 1903—September 2, 1966) was an American politician and attorney from the U.S. state of Rhode Island. McGrath, a Democrat, served as District Attorney before becoming Governor, U.S. Senator, chairman of the Democratic National Committee, and U.S. Attorney General

McGrath was born in Woonsocket. He graduated from La Salle Academy in 1922, from Providence College in 1926, and from Boston University in 1929. From 1930 to 1934 he was the city solicitor of Central Falls, Rhode Island. During this time he was also interested in the real estate, insurance, and banking industries. He served as U.S. District Attorney for the District of Rhode Island from 1935 to 1940.

From 1940 until 1945 he was Governor of Rhode Island. McGrath served as Solicitor General of the United States from 1945 to 1946. He was chairman of the Democratic National Committee from 1947 to 1949.

He was elected as a Democrat to the United States Senate from Rhode Island in 1946. He was chairman of the U.S. Senate Committee on the District of Columbia for the 81st Congress .

President Harry Truman appointed McGrath Attorney General of the United States on August 24, 1949. He resigned from that office on April 7, 1952 and entered the private practice of law in Washington, D.C. and Providence. He was an unsuccessful candidate for nomination as United States Senator in 1960.

McGrath died in Narragansett, Rhode Island in 1966 and is buried in St. Francis Cemetery, Pawtucket, Rhode Island.