|Relatives:||Mary Grayson (wife, deceased), Dick Grayson (son)|
|Voiced by:||Thomas F. Wilson (uncredited)|
John Grayson was the father of Dick Grayson.
In an attempt to convince Mr. Haley to pay "insurance", Tony Zucco sabotaged the trapeze. During the show, in front of the entire crowd and young Dick, John and Mary fell to their deaths when the line snapped.