Osmium(V) chloride is an inorganic chemical compound of osmium metal and chlorine with the chemical formula .
Osmium(V) chloride can be obtained in small amounts by reacting osmium hexafluoride with excess boron trichloride:
It can also be obtained by the action of sulfur dichloride on osmium tetroxide:
Osmium(V) chloride forms a black dimeric solid, isomorphic with rhenium(V) chloride. is sparingly soluble in non-polar solvents. It is soluble in POCl<sub>3</sub> to form a red-brown solution, which can crystallize OsCl<sub>5</sub>÷POCl<sub>3</sub>.