Hovhannes Erznkatsi (Armenian: Հովհաննես Երզնկացի — John of Erznka or Erzinjan) (c. 1250 – 1326) was nicknamed Blouz, probably because of his short stature.
The little that has reached us of his voluminous works reveal an exceptionally gifted scholar, with treasured knowledge of vast scope. Living mostly in the latter part of the thirteenth century, he was also the last of the higher class of the Armenian authors of the ancient and medieval ages. Erznkatsi wrote hymns, commentaries, odes, eulogies, a Martyrology, an astronomical treatise on celestial elements, and a grammar. He was personally known and honored in almost every center of learning in Greater Armenia and Cilicia.