Gezienus (or Gesinus) ten Doesschate (11 August 1885, Zwolle – 9 March 1965, Utrecht) was a Dutch ophthalmologist, amateur painter and historian. He was active as an amateur painter in Utrecht under the pseudonym Thomas Denier. He had good contacts with the cultural elite of Utrecht around the First World War and was good friends with the painters Janus de Winter and . In 1916 he was briefly a member of de Anderen, a Dutch artists' group that included Theo van Doesburg, but dropped out in support of de Winter, another artists group.