Gelert, also spelled Gellert or Killhart, was a 13th-century dog of Welsh fable.

Gelert may also refer to:

Gelert (company), a company selling outdoor equipment Elżbieta Gelert (born 1955), Polish politician Otto Gelert (1862–1899), Danish botanist and pharmacist Saint Gelert (7th century), probable founder of Beddgelert and Llangeler, in Wales Gelert's Farm Works, British railway operating center Gelert's Farm halt, British railway platform Gelert, a type of pet in Neopets

See also Gellert (disambiguation)