Frank Schaefer was pastor of the United Methodist Church in Lebanon County when he was found guilty by a church jury of breaking laws in 2013 for officiating his son's gay wedding in 2007.
He refused to say that he would never perform another gay marriage and was defrocked before being reinstated in June this year on appeal.
Conservative members of the United Methodist Church then appealed the decision to reinstate him.
This led to him having to attend a hearing before the Judicial Council - the Methodist Church's highest legal body - last Wednesday, regarding whether his reinstatement would stand.
However, the Judicial Council has ruled in favour of reinstating Rev Schaefer on a technicality, therefore making his reinstatement permanent.
They reaffirmed that the United Methodist Church does not support same-sex marriage.
Frank Schaefer told the Daily Mail: "This is a positive decision that keeps the dialogue going.
"They didn't bar a person who is an outspoken activist and who has said that, if asked, he would perform another gay marriage.
"I did what I did based on my heart and my conscience."
Schaefer, who has three gay children, chose not to testify at his hearing.
Rev Christopher Fisher, who argued against Schaefer's reinstatement at the hearing, said that deciding to reinstate him after suspending him "sends a message to the Church that it's OK to ignore and violate the discipline".
Several people wearing rainbow scarves - the colours traditionally associated with gay pride - attended Schaefer's hearing in solidarity.
The United Methodist Church is North America's second-largest Anglican denomination.