The Invisible Boy

Timmie Merrinoe

Dr. Tom Merrinoe

Mary Merrinoe

Gen. Swayne

Prof. Frank Allerton

Col. Macklin

Arthur Kelvaney

Prof. Baine

Dr. Bannerman

Prof. Zeller

Prof. Foster

Martin / Computer

1st Gate Sergeant

2nd Gate Sergeant

Capt. McLaren (uncredited)

Miss Vandergrift (uncredited)

Scientist (uncredited)

Young soldier (uncredited)

Robby the Robot (voice) (uncredited)

Robby