A native of Quatre-Bornes, Mauritius, Margéot was ordained as a priest on December 17, 1938. He was consecrated as Bishop of the Diocese of Port-Louis on May 4, 1969 and served until February 15, 1993. He was President of the Conférence Episcopale de l'Océan Indien from 1986-1989. Margéot was elevated to be a Cardinal by Pope John Paul II on June 28, 1988 becoming Cardinal-Priest of San Gabriele Arcangelo all′Acqua Traversa, the first Cardinal from Mauritius. Following his death in 2009 at the age of 93, Margéot was lauded by Pope Benedict XVI in a public statement.
He was widely respected for evangelizing by public witness, and extremely active in the formation of the clergy. Along with his involvement in the formation of the young and catechists, he provided spiritual guidance for the Chinese and Indian communities within the diocese's territory.