The Collaborative International Dictionary of English v.0.48:

Self-reliant \Self`-re*li"ant\, a.
   Reliant upon one's self; trusting to one's own powers or
   judgment.
   [1913 Webster]

WordNet (r) 3.0 (2006):

self-reliant
    adj 1: (of persons) free from external control and constraint in
           e.g. action and judgment [syn: autonomous, self-
           directed, self-reliant]

Moby Thesaurus II by Grady Ward, 1.0:

64 Moby Thesaurus words for "self-reliant":
   arrogant, assured, autarchic, autarkic, autonomous, cocksure,
   confident, convinced, decided, determined, erect, free-spirited,
   freewheeling, house-proud, hubristic, independent, individualistic,
   inner-directed, neutral, nonaligned, nonpartisan, overconfident,
   oversure, overweening, persuaded, poised, pompous, positive,
   prideful, proud, proud as Lucifer, proud-blooded, proud-looking,
   proud-minded, proud-spirited, proudful, proudhearted, purse-proud,
   reassured, secure, self-assured, self-confident, self-contained,
   self-dependent, self-determined, self-directing, self-esteeming,
   self-governed, self-governing, self-important, self-respecting,
   self-subsistent, self-sufficient, self-supporting, sovereign,
   stiff-necked, sure, third-force, third-world, unafraid, undoubting,
   unfaltering, unhesitating, unwavering