Dukecynus is an extinct genus of meat-eating metatherian belonging to the order Sparassodonta, which lived in South America during the Middle Miocene (Laventan), between about 13.8 and 11.8 million years ago.

Dukecynus is only known from its holotype, IGM 251149, a heavily damaged partial skull preserving parts of the lower and upper jaw as well as associated fragments of the skeleton.

[1] This specimen was discovered at the Konzentrat-Lagerstätte La Venta in the Honda Group, Huila and Tolima in Colombia.

[1][2] Although the affinities of this species have never been formally analysed, Dukecynus is generally considered to be a basal borhyaenoid, a paraphyletic group of sparassodonts that includes genera like Lycopsis and Prothylacynus that cannot be assigned to one of the major borhyaenoid families like Borhyaenidae or Thylacosmilidae.

[3] Compared to other basal borhyaenoids, Dukecynus had a long, narrow snout and was relatively large, with some estimates suggesting this animal weighed up to 68 kilograms (150 lb).