self-assurance 
noun [mass noun]
Confidence in one’s own abilities or character: his air of self-assurance...
- In all the pictures, she's got a striking air of confidence and self-assurance about her.
- Their confidence and self-assurance is indeed palpable, as is their ability to express themselves uninhibitedly.
- He plays the role with a mixture of sadness and self-assurance that makes his character the most memorable in the picture.
Synonyms
self-confidence, confidence, belief in oneself, positiveness, assertiveness, assurance, self-reliance, self-possession, composure, nerve, poise, presence, aplomb