To provide an elevator main rope coming-off prevention device mountable with simple work regardless of a winding angle and direction of a main rope with respect to a sheave, and of the type of a hoisting machine.

The elevator main rope coming-off prevention device is provided with: a rotating body 1; a main rope groove 2 provided on the rotating body 2; the main rope 3 wound around the main rope groove 2; a pair of fitting members 6 slidably engaged with the rotating body 1; and a main rope suppressing member 7 which is fixed to a space between free ends of the pair of fitting members 6, slidably guides the main rope 3 released and extended from the main rope groove 2 of the rotating body 1 to the extension direction, suppresses a shift of the main rope 3 to the direction orthogonal to the extension direction, and also suppresses coming off of the main rope 3 from the main rope groove 2.