He was a government representative, honorary judge of the Court of Mexico. He was the son of Rosalía Gómez Gaona and Ignacio Obregón. His family had some connections with Viceroy Iturrigaray, and when the latter was overthrown, Octaviano and his brother Ventura immigrated to Spain.

He studied Latin, Rhetoric and three years of Philosophy at the Seminary of Guadalajara. Thus, he received a Bachelor's degree of Arts in 1799. He then studied at the Royal and Pontifical University of Mexico, graduating with a Bachelor's degree in Canons in 1803, and in Law in 1804. In 1807 he entered the Royal Bar Association of Mexico. While he was already living in the Iberian Peninsula, he was appointed honorary speaker on March 8, 1810. Eight days later he was promoted to supernumerary judge.

He began working as the alternate government representative of the province of Santa Fe de Guanajuato (viceroyalty of New Spain) in the Cortes of 1810 (parliament) on September 24th, and became an official representative on December 23rd. He was a supporter of free trade and the abolition of the Tribunal of the Holy Office (Spanish Inquisition). He was one of the few Latin American representatives who agreed that America should also contribute to war expenses. He was very critical of the Spanish colonization process in the Indies.

He was one of the signatories of the Constitution, and was again a representative in the Cortes of 1813. In 1814 he was accused of being a Mason.

On October 8, 1821, Ferdinand VII appointed him Judge of the Royal Audience of Guadalajara, and the first emperor of Mexico, Agustín de Iturbide, ratified his position. In 1828 he became a member of the Junta Patriotica, and in 1829 a member of the Mexican Society of Agricultural Manufacturing Industry.