The sandwich was created by a McDonald's franchise owner in Cincinnati, Ohio, named Lou Groen in 1962.[6][7] Groen owned a McDonald's in a predominantly Roman Catholic neighborhood where his Catholic customers engaged in the practice of not eating meat on Fridays[7] (a practice mandated before Vatican II but that the Catholic Church continues to consider obligatory on Fridays during Lent).[8]The product was named by Cye Landy of Cye Landy Advertising Agency, which was the advertising firm for that particular McDonald's franchise.
It has become popular with people with dietary restrictions concerning meat-based products. For example, in Judaism, the fish used in the sandwich is considered kosher even without special preparation, whilst other meats would require special slaughter techniques to be considered kosher.[9]
The sandwich was the first non-hamburger menu item brought in by new McDonald's company owner Ray Kroc.[10] Kroc made a deal with Groen: they would sell two non-meat sandwiches on a Friday, Kroc's own Hula Burger (grilled pineapple with cheese on a cold bun) and the Filet-O-Fish, and whichever sold the most would be added to the permanent menu. The Filet-O-Fish "won hands down"[7] and was added to menus throughout 1963 until reaching nationwide status in 1965.[11]
I just liked the sandwich.