Thomas Louis Heylen OPraem (1856–1941) was a Belgian prelate of the Catholic Church who served as the twenty-sixth bishop of Namur in Belgium (1899–1941).

He was ordained to the priesthood on 11 January 1881 in Mechelen and was sent to Rome to study philosophy, theology, and canon law.

[2] As abbot he founded Corpus Christi Priory in Manchester and a Premonstratensian mission post in Congo Free State.

His emphasis was on encouraging religious devotion, promoting both mass pilgrimages and private retreats among the laity and emphasizing ongoing formation for the clergy.

[2] In 1901 he became president of the Pontifical Committee for International Eucharistic Congresses, in succession to Victor Joseph Doutreloux, bishop of Liège.