Attorneys for the unnamed plaintiff say their client was abused for three years beginning in 1996 while an altar boy at Incarnation of Our Lord Parish in north Philadelphia.
The suit names Father William Ayres, who the attorneys say was at a Wynnewood seminary at the time and was sent to Incarnation as a priest after he was ordained in 1999. The archdiocese and other top officials also are named.
Attorneys say that when the plaintiff reported the abuse to the current parish pastor, he was told that Ayres "was already under investigation and there had been reports filed before the plaintiff's abuse had occurred."
The suit alleges sex abuse, conspiracy and negligence on the part of church officials and seeks more than $50,000.
The Philadelphia Inquirer says the suit is at least the ninth filed by an alleged victim of clergy abuse since February, when four current and former priests were arrested and a grand jury report criticized the handling of abuse complaints.
Ayres, who was removed from active ministry in November, did not return a call seeking comment Wednesday. Archdiocese spokesman Kenneth Gavin declined comment.