biographer

from WordNet (r) 3.0 (2006)

biographer
    n 1: someone who writes an account of a person's life

from The Collaborative International Dictionary of English v.0.48

Biographer \Bi*og"ra*pher\, n.
   One who writes an account or history of the life of a
   particular person; a writer of lives, as Plutarch.
   [1913 Webster] Biographic