Osteocephalus duellmani is a frog in the family Hylidae endemic to Ecuador.

Scientists know it exclusively from its type locality in the Cordillera del Cóndor.

[1][2] The sole adult male sample measured 48.1 mm long in snout-vent length.

[2] This frog lives in dense cloud forests with high humidity.

The area was full of trees covered in moss and epiphytes.