WordNet (r) 3.0 (2006):

sun worshiper
    n 1: someone who worships the sun

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "sun worshiper":
   Druid, Parsi, Sabaist, Zoroastrian, animal worshiper,
   anthropolater, arborolater, archaeolater, chthonian,
   demon worshiper, demonolater, dendrolater, devil worshiper,
   fetishist, fire worshiper, idol worshiper, idolater, idolatress,
   idolatrizer, idolist, idolizer, nature worshiper, ophiolater,
   phallic worshiper, pyrolater, snake worshiper, star worshiper,
   theriolater, therolater, tree worshiper, zoolater