The Collaborative International Dictionary of English v.0.48:

Upholsterer \Up*hol"ster*er\, n. [A substitution for older
   upholder, in OE., broker, tradesman, and formerly also
   written upholster, upholdster. See Upholder, and
   -ster.]
   One who provides hangings, coverings, cushions, curtains, and
   the like; one who upholsters.
   [1913 Webster]

   Upholsterer bee. (Zool.) See Poppy bee, under Poppy.
      [1913 Webster]

WordNet (r) 3.0 (2006):

upholsterer
    n 1: a craftsman who upholsters furniture