The Collaborative International Dictionary of English v.0.48:

Narrator \Nar*ra"tor\, n. [L.]
   One who narrates; one who relates a series of events or
   transactions.
   [1913 Webster]

WordNet (r) 3.0 (2006):

narrator
    n 1: someone who tells a story [syn: narrator, storyteller,
         teller]