Dr. Maximilianus Rex (born 23 September 1973) is an Indonesian Catholic prelate.

Max was born in Manggarai, East Nusa Tenggara, Indonesia, on 23 September 1973.

He attended the Pius XII Pontifical Roman Minor Seminary and carried out his studies in philosophy and theology at the Saint Petrus-Ritapiret Pontifical Major Seminary in the diocese of Maumere on 1992.

After his priestly ordination, he assigned as the associate pastor to the Christ the King parish church (2001–2007), chairman of the diocesan Commission for youth pastoral care, and member of the diocesan Commission for interreligious dialogue (2002–2007).

[4][5] On 21 June 2024, The Roman Catholic Diocese of Labuan Bajo in West Manggarai Regency has been erected from The Roman Catholic Diocese of Ruteng in Manggarai Regency, and he has been appointed as its first bishop.