Hemingwaya is an extinct genus of billfish in the monotypic family Hemingwayidae that lived during the earliest Eocene epoch, approximately 56 to 55 million years ago.

It is known from the Danata Formation of Turkmenistan, which represented a far eastern inland arm of the Tethys Ocean, and was deposited in the earliest Eocene shortly after the Paleocene-Eocene Thermal Maximum.

[2] The genus name honors famed author Ernest Hemingway, who prominently featured a marlin in his 1952 novella The Old Man and the Sea, while the species name "sarissa" originates from the Greek word for "spear".

[3] The fossils of Hemingwaya provide insight into the early evolution of billfishes, representing one of the first known lineages to exhibit the characteristic bill-like morphology.

While the exact diversity within the family is limited, the fossil record indicates that Hemingwaya were part of the evolutionary stem group that led to the development of modern billfishes.