William Joseph Green Jr. (March 5, 1910 – December 21, 1963) was a Democratic member of the U.S. House of Representatives from Pennsylvania.

Green was born in Philadelphia, Pennsylvania, the son of Irish immigrants.

He served in the United States Army as a private in the Quartermaster Corps from March 22, 1944, to December 4, 1944.

Green died of peritonitis and gall bladder complications in Philadelphia on December 21, 1963[2] and was interred at Holy Sepulchre Cemetery in Cheltenham Township, Pennsylvania.

Green Jr. Federal Building, at 6th and Arch streets in Philadelphia, is named for him.