Bishop Janusz Stepnowski was born on 11 July 1958 in Ostroleka, Poland. He studied philosophy and theology at the Major Seminary in Lomza from 1979 to 1985. His studies were interrupted for six months by compulsory military service imposed by the communist government. He was ordained a priest on 1 June 1985. After his ordination, he was sent to study at the University in Pamplona (Spain), graduating in 1989 with a doctorate degree in Canon Law. He then went to Italy where he worked in pastoral care in the Diocese of Terni.
In Rome, apart from his service at the Congregation for Bishops, he has worked for the Tribunal of the Roman Rota.
In 2011 he was appointed Bishop of Lomza (Poland), his native Diocese.
Mgr. Stepnowski is the Polish Bishop Delegate to COMECE since 2012.