Healy was cited following an incident in the 17th minute of the Western Force v British & Irish Lions match in Perth on Wednesday under law 10.4 m - acts contrary to good sportsmanship against Western Force scrum half Brett Sheehan.
Hearing the case judicial officer, Nigel Hampton QC, found insufficient evidence to support the allegations and cleared Healy, who attended the hearing with Brian O'Driscoll, the Lions' captain against Western Force, and tour manager Andy Irvine.
In his findings, Hampton stated that on the balance of probabilities he was not satisfied that Healy bit former Australian international Sheehan.
"There is no conclusive video evidence of the incident and post-match it was not possible to distinguish any discernible bite marks outside of the 'regular' marks usually found following a rugby match," Hampton said in his findings.
"I cannot find proven on the balance of probabilities that there was a deliberate bite here, and the citing complaint is not upheld."
Hampton determined that during the tackle Sheehan's arm may have come in contact with Healy's mouth and due to the pressure of the tackle it is likely that unavoidable contact between Healy's mouth and teeth and Sheehan's arm occurred.
Giving his reaction to being cleared, Healy said: "I am very relieved that the hearing has cleared me of such an allegation. I was naturally very disappointed that there was a citing in the first place.
"I always maintained that nothing happened and that I had done nothing illegal. The opposition player's arm hit me. It is as simple as that.
"The support I had from the management and all the lads was wonderful and I am glad that it is all over."
Lions tour manager Andy Irvine added: "We're very pleased with the outcome of today's judicial hearing in Brisbane.
"Mr. Hampton was extremely fair and thoroughly considered all the facts of the case in great detail. We always believed that Cian had done nothing wrong and had not acted maliciously in any way.
"The decision was important to the player's and indeed squad's integrity as the allegation was a serious one."
The decision means Healy is free to play for the Lions, however his availability will depend on the hospital scan he underwent following the hearing.
He damaged his left ankle when being tackled from Western Force flanker Angus Cottrell in the first half and had to be taken off.
The Leinster and Ireland prop is currently awaiting results of the scan. The Lions management have opted to call up England's Alex Corbisiero to act as precautionary cover.