Leon Lemmens (16 March 1954 – 2 June 2017) was a Roman Catholic auxiliary bishop in Belgium.

He was named an auxiliary bishop to the Archdiocese of Mechelen-Brussels by Pope Benedict XVI on 22 February 2011 and consecrated on 3 April 2011.

[3] In 2004 he became rector of the Romanian College in Rome and in 2005 he was an official at the Sacred Congregation for the Oriental Churches of the Roman Curia.

[4] On 22 February 2011, pope Benedict XVI appointed Lemmens as auxiliary bishop in the archdiocese of Mechelen-Brussels, with the responsibility for the vicariate Vlaams-Brabant & Mechelen.

[5][6] He was consecrated on 3 April 2011 in the National Basilica of the Sacred Heart in Koekelberg by archbishop André-Joseph Léonard.