The Collaborative International Dictionary of English v.0.48:

Formalist \Form"al*ist\, n. [Cf. F. formaliste.]
   One overattentive to forms, or too much confined to them;
   esp., one who rests in external religious forms, or observes
   strictly the outward forms of worship, without possessing the
   life and spirit of religion.
   [1913 Webster]

         As far a formalist from wisdom sits,
         In judging eyes, as libertines from wits. --Young.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

68 Moby Thesaurus words for "formalist":
   Babbitt, High-Churchist, Holy Willie, Joseph Surface, Mawworm,
   Middle American, Pecksniff, Pharisee, Philistine, Sabbatarian,
   Tartuffe, Vicar of Bray, affecter, anal character, bluestocking,
   bourgeois, burgher, canter, canting hypocrite, chameleon,
   compulsive character, conformer, conformist, conventionalist,
   dissembler, dissimulator, formularist, formulist, hypocrite,
   lip server, lip worshiper, liturgist, methodologist,
   middle-class type, model child, organization man, parrot, pedant,
   perfectionist, pharisee, pietist, pious fraud, plastic person,
   poser, precieuse, precieux, precisian, precisianist, precisionist,
   purist, ranter, religionist, religious hypocrite, ritualist,
   sacramentarian, sheep, sniveler, snuffler, spiritual humbug,
   square, teenybopper, temporizer, timepleaser, timeserver, trimmer,
   weathercock, whited sepulcher, yes-man