A key lock handle (1) for doors and windows comprises at least: a handle casing (2) that can be fixed to the door or window sash and presenting, on one side, a protruding portion (3) from which there projects a handgrip (4) by which a spindle (5) housed inside the handle casing (2) can be rotated about an axis (Y) transversal to the handle casing (2) from at least a first position to a second position and vice versa; the other side of the handle casing (2) presenting operating means (6) engageable with a sash closing device in such a way as to determine an open configuration and a closed configuration of the sash; key lock means (7) being provided to operate between the handgrip (4) and the handle casing (2), and comprising engagement / disengagement means (8) acting on the handgrip (4) in such manner that, when the handgrip (4) is in the open configuration, it is engaged with the operating means (6), and when the handgrip (4) is in the closed configuration, it is disengaged from the operating means (6) and from the handle casing (2) so that it can turn freely about the transversal axis (Y) if an attempt is made to force the handgrip (4) itself.