Union Block may refer to:

Union Block (Mount Pleasant, Iowa) Union Block (Fort Scott, Kansas), listed on the NRHP in Bourbon County, Kansas Union Block (Oskaloosa, Kansas) Union Block (Lewiston, Maine) Union Block (Buchanan, Michigan) Union Block (Saline, Michigan) Union Block (Mayville, North Dakota) Union Block (Nunda, New York) Union Block (Lima, Ohio) Union Block (Newberg, Oregon), listed on the NRHP in Yamhill County, Oregon Union Block (Brigham City, Utah)

See also Union Block and Montandon Buildings, Boise, Idaho Union blockade