Józef Sebastian Pelczar (17 January 1842 – 28 March 1924) was a Polish Roman Catholic bishop and was also the co-founder of the Sister Servants of the Most Sacred Heart of Jesus which he had established in 1894 with Ludwika Szczęsna.

While in Krakow in 1893 he met Ludwika Szczęsna and the two established the Sister Servants of the Most Sacred Heart of Jesus on 15 April 1894 with the aim of working with women.

He also conducted three episcopal meetings to discuss diocesan issues and worked to reform seminaries to promote better education and greater access to resources for them.

He ensured that the implementation of the social doctrine described in the writings of Leo XIII — such as the papal encyclical Rerum Novarum - was a top priority.

Pelczar died on 28 March 1924 with a strong reputation for holiness and was hailed as a shepherd who paid close attention to pastoral issues.

Pope John Paul II approved that Pelczar had lived a life of heroic virtue and declared him to be Venerable on 18 February 1989.