OSW may refer to:
Centre for Eastern Studies, a Polish think tank FAL OSW, a variant of the FN FAL folding-stock paratrooper rifle Objective Sniper Weapon, the original name of the Barrett XM109 Official Scrabble Words, a Scrabble lexicon Open Spatial Workshop, a group of three Australian artists, winner of the 2005 Melbourne Prize for Urban Sculpture Office of the Secretary of War