Roman Catholic priest, was born in Kilrea, Co Londonderry, on 1 May 1863 (or possibly 2 April 1863), the son of Manus Diamond and Isabel, née O'Fee. He went to the local elementary school, then continued into secondary education at St McCartan's College in Monaghan. In 1881, at the age of eighteen, Patrick Diamond decided to become a priest and travelled to Turin in Italy to the Religious Congregation of Salesians, the Congregation of Priests and Brothers recently founded by Don John Bosco. There he began six years of study to become a priest. Later that same year, he was sent to South America, and continued his studies in Buenos Aires. He made his religious profession as a member of the Salesian Congregation on 9 February 1884.

In October 1887 he was ordained priest. His first appointment was to teach in one of the Salesian schools in Buenos Aires. Six months later he was appointed to the Falkland Islands where there had not been a priest since the departure of Fr James FORAN in 1886. Diamond arrived in the Falkland Islands on 19 April 1888. He was young and inexperienced both as a priest and as a teacher, but set to work ministering to the spiritual needs of the Catholic population, visiting them in their homes, gathering them for Mass and preparing them for reception of the sacraments. He belonged to a Congregation which had been founded in 1859 to provide education and training for young people. To re-establish the Catholic school was one of his priorities. Eighteen months into his mission, Diamond had built a mission house that also served as a school. To the money which the Catholic congregation raised for these purposes, he made a large contribution from his own savings. At the end of 1889 it was recorded that he was in charge of the school comprising some sixty boys and girls and was teaching four hours daily.

Fr Diamond moved to Punta Arenas to become superior in the Salesian Mission House there, and then back again to the Falklands. He finally left the Falklands in 1905, worked in a New York parish until 1921, then in San Francisco until 1937. He died in San Francisco on 26 March 1937.

That Fr Diamond was the priest sent to the Falkland Islands as the trailblazer for the Salesian Mission tells us of the confidence his religious congregation had in him. He was young, not yet twenty-five years old, and only six months a priest. He saw his work as three-fold: to build up the Catholic community; to establish a mission house that would serve as a centre for his Catholic congregation; and to provide education for the young people of the Falklands, irrespective of their religion. What he accomplished in the first eighteen months after his arrival marks him as a man of action, capable of seeing what needed doing and setting out to accomplish it in a way that would benefit the whole Falklands community. He had built his mission house and was running a school for upwards of sixty pupils. He laid a foundation on which future Salesian priests and Sisters would build. The School closed in 1941, but St Mary's parish flourishes.