Father Jan Nikiel was born in Wilkowice, Śląsk province. In 1980 finished State Music School after which entered the High Seminary in Krakow where has studied on theology faculty of Pope Theology Academy. He received the ordination from cardinal Franciszek Podhalanski in Wawel Cathedral on 17 May 1987. After the ordination he had been working in Makow Podhalanski for three years. Then for a year he had been working in Czarny Dunajec.
In 1991 left to work in Lviv Diocese in Ukraine. He had been working in Stryy, Skole, Berezdiwci (till 1993), Zhydachiv (till 1993). Also he was a president of Caritas-Spes from 20 January 2003 to August 2009. He was appointed the rector of Lviv Archcathedral and the dean of Lviv deanery on 1 August 2009.