The fifth child of Domingos Vaz Filipe and Ermelinda Baptista Filipe, Carlos Felipe Ximenes Belo was born in the village of Wailakama, near Vemasse, on the north coast of East Timor. His father, a schoolteacher, died two years later. His childhood years were spent in Catholic schools at Baucau and Ossu, before he proceeded to the Dare minor seminary, outside Dili, from which he graduated in 1968. From 1969 until 1981, apart from periods of practical training (1974 - 1976) back in East Timor and in Macau, he was in Portugal and Rome where, having become a member of the Salesian Society, he studied philosophy and theology before being ordained a priest in 1980.
Returning to East Timor in July, 1981 he became a teacher for 20 months, then Director for 2 months, at the Salesian College at Fatumaca. On the resignation of Martinho da Costa Lopes in 1983, Carlos Filipe Ximenes Belo was appointed Apostolic Administrator of the Dili diocese, becoming head of the East Timor church and directly responsible to the Pope. In 1988 he was consecrated a Bishop (of Lorium, Italy).
Father Belo was the choice of the Vatican's Pro Nuncio in Jakarta and the Indonesian leaders because of his supposed submissiveness, but he was not the choice of the Timorese priests who did not attend his inauguration. However within only five months of his assuming office he protested vehemently, in a sermon in the cathedral, against the brutalities of the Kraras massacre (1983) and condemned the many Indonesian arrests. The church was the only institution capable of communicating with the outside world, so with this in mind the new Apostolic Administrator started writing letters and building up overseas contacts, in spite of the isolation arising from the opposition of the Indonesians and the disinterest of most of the world and the Catholic Church.
In February, 1989 he wrote to the President of Portugal, the Pope, and the UN Secretary-General, calling for a UN referendum on the future of East Timor and for international help for the East Timorese, who were "dying as a people and a nation", but when the UN letter became public in April, he became even more of a target of the Indonesians. This precariousness increased when Bishop Belo gave sanctuary in his own home, as he did on various occasions, to youths escaping the Santa Cruz massacre (1991), and endeavoured to expose the numbers of victims killed.
Bishop Belo's courageous labours on behalf of the East Timorese and in pursuit of peace and reconciliation were internationally recognised when he was awarded, along with Jose Ramos-Horta, the prestigious Nobel Peace Prize in December, 1996. Bishop Belo capitalised upon this honour through meetings with Bill Clinton of the United States and Nelson Mandela of South Africa.
In the aftermath of East Timorese independence in May 2002, the pressure of events and the ongoing stress he endured began to show their effects on Bishop Belo's health. Pope John Paul II accepted his resignation as Vicar Apostolic of Dili on November 26, 2002.