The Grand Army of the Republic Hall, also known as the General Frederick W. Lander Post No. 5, Grand Army of the Republic, is an historic building located at 58 Andrew Street in Lynn, Massachusetts, in the United States. The hall was built in 1885 by members of the Grand Army of the Republic as a memorial to the Union Army veterans of the Civil War. It was one of many such halls built in the country. On May 7, 1979, it was added to the National Register of Historic Places. The hall is now the Grand Army of the Republic Museum.