What Came First Gorilla Grodd Or Planet of the Apes?

Gorilla Grodd predates Planet of the Apes by 4 years.

Grodd appeared in FLASH #106, Apr- May 1959 http://en.wikipedia.org/wiki/Gorilla_Grodd.

The French novel PLANET OF THE APES http://en.wikipedia.org/wiki/Planet_of_the_Apes_(novel) was published in 1963. Four years after the appearance of Gorilla Grodd.

Gorilla City, the place that most resembles the city in Planet of Apes movie, also appeared in FLASH #106.

Jack Kirby's KAMANDI was a nod to PLANET OF THE APES after DC Comics could not retain rights to the Book and Movie.

 Ironically Kirby had already wrote a similar story to it in 1956 for Harvey Comics.
See this link for more info about KAMANDI and the Harvey story by Kirby: http://en.wikipedia.org/wiki/Kamandi.

So there PLANET OF APES.  GORILLA GRODD is king of the talking Apes.

Go Forth and Do Well

Shane.