A downspout guard having opposed sidewalls and opposed end walls connected to a top wall, all formed from mesh material, such as metal mesh. Bottom edges of the walls engage a gutter bottom wall to hold the guard in place and forcing water to flow through the guard before entering the downspout. The sidewalls can engage gutter front/back walls, further holding the guard in place. Trapped debris enhances further debris entrapment, even trapping particles smaller than the mesh opening. Optionally, end walls taller than the sidewalls to accommodate obstructions and allow height adjustment by relative angle changes.