Antonyms of unfairness:
candor, candour, equity, fair-mindedness, fairness, faithfulness, impartiality, lawfulness, righteousness, honesty, integrity, rectitude, uprightness, fair play, honor, justice, right, cricket, equitableness.
Examples of usage:
  1. My father, unable to overcome his fatal shyness by any effort of will, had not the courage to withstand this unfairness until he was called home by his mother for his twenty- fifth birthday, and made use of the elixir.
    "The Complete Historical Romances of Georg Ebers", Georg Ebers.
  2. Not the pain of this but its unfairness was what dazed Peter.
    "Peter and Wendy", James Matthew Barrie.
  3. Regretting immensely that Mr. Tuckham had not reached England earlier, that he might have occupied the seat for Bevisham, about to be given to Captain Baskelett, Colonel Halkett set up a contrast of Blackburn Tuckham and Nevil Beauchamp; a singular instance of unfairness, his daughter thought, considering that the distinct contrast presented by the circumstances was that of Mr. Tuckham and Captain Baskelett.
    "The Complete Project Gutenberg Works of George Meredith", George Meredith.