He was a presbyter, diplomat, bishop and representative. He was the eighth of nine children born to the married couple of Simón de Larrazábal Gálvez, perpetual alderman of the City Council of Guatemala, and María Ana Arrivillaga Montúfar. He began his studies at a very young age with a bachelor's degree in Philosophy and finished them with a doctorate in Theology and Sacred Canons. He became rector of the University Of San Carlos. His ecclesiastical career, which began as a deacon, led him to later become the Vicar and Governor of the Archdiocese of Guatemala.

In 1810 he was elected Government Representative of the province of Guatemala, and then again in 1813 but this time as an alternate. His work in the Cortes (parliament) was important, and he even became president of it. He used his status as representative to defend some instructions drawn up by the creoles of the city council of Guatemala, which reflected a number of fundamental ideas. Larrazábal defended the rights of Latin Americans of being represented in the Cortes, the freedom of trade of the American provinces and the suppression of the Inquisition, as well as the return of the Society of Jesus. He was also a strong defender of the American Indians and their citizenship, as well as their necessary education. Actually, his position was not only a defense of the dignity of this group, but also a way of increasing the representativeness of the American provinces thanks to their greater population density.

With the return of Fernando VII, Larrazábal's political stance led to his persecution and condemnation. His sentence of five years in prison was partially served in America thanks to the intercession of the Guatemalan Cabildo. With the constitutional restoration of 1820, Larrazábal regained his freedom and was the focus of tributes in Guatemala. He defended the independence of Guatemala and always considered that it should be total and not dependent on a federal state with Mexico. Hence, in 1822 he resigned as a representative in the Cortes of the Empire of Mexico for the party of Chimaltenango. In 1825 he was appointed minister plenipotentiary to attend the General Assembly of the Independent Countries of America. He returned to Guatemala in the 1830s and became a bishop.