According to the invention, there is provided a hybrid maize plant, designated as 37K84, produced by crossing an inbred maize line with a Pioneer Hi-Bred International, Inc. proprietary inbred maize line. This invention relates to the hybrid seed 37K84, the hybrid plant produced from the seed, and variants, mutants, and trivial modifications of hybrid 37K84. This invention also relates to methods for producing a maize plant containing in its genetic material one or more transgenes and to the transgenic maize plants produced by those methods. This invention further relates to methods for producing maize lines derived from hybrid maize line 37K84 and to the maize lines derived by the use of those methods.