The Church's legal sub-committee investigated a letter signed by five insiders who claimed highlighting the sexuality of one candidate, Dr Jeffrey John (pictured), "prejudiced" proceedings.
Investigating three complaints in total, chair His Honour Judge Andrew Keyser QC, concluded: "All three complaints are without merit.
"The proper course is for the bishops to proceed to fill the vacancy in accordance with Regulation 23 and the exercise of their own judgment."
The announcement by Judge Andrew comes after five members of the Church in Wales' electoral college, the body which discusses and votes on bishop candidates, complained.
They said: "We object to the raising at electoral college of the matter of sexuality or civil partnership status, in direct contravention of the Church in Wales's own policy that sexuality or civil partnership status is not a bar to appointment as a Bishop.
"We consider that this action was deeply inappropriate, and prejudiced the electoral college proceedings so as to render them invalid."
The Church in Wales has said neither homosexuality nor participation in a civil partnership prevent any candidate being either nominated or elected as a Bishop in the Church in Wales.
It has confirmed the selection process will now resume, with the decision regarding a new Bishop of Llandaff being made by the Bench of Bishops after the college failed to elect someone within three days.
The Provincial Secretary of the Church in Wales, Simon Lloyd, said, "I am very grateful to the legal subcommittee for their thorough and prompt examination of the complaints received about the election and appointment process of the Bishop of Llandaff.
"I can now confirm that proper procedure has been followed and there are no grounds for the complaints submitted.
"This means the Bench of Bishops can continue its task of appointing the new bishop without further delay."