EWTN Catholic Q&A
The order that Pope Benedict XVI entered when he became a priest.
Question from Tom Tarcson on 04-20-2005:

What order did Pope Benedict XVI enter into when he became a priest on June 29, 1951? Is he a priest in the Benedictine Order?

Answer by Colin B. Donovan, STL on 04-25-2005:

No, he is a diocesan priest, of Munich, his home dicoese. To my knowledge he has never entered a religious order.