He was born at Calonne-sur-la-Lys near Béthune in what was the county of Flanders and the Duchy of Burgundy. He and his brother Christophe lost their father at an early age, and his mother placed him in the Trinitarian convent of Préavin, where he began his studies. He later attended the University of Paris.
In his later years, he published a reformation of the statues of the Trinitarian Order on August 30, 1497. He died in Paris on May 22, 1501 at the age of sixty-seven and was interred at the church of the convent of the Trinitarians.
He also translated several works from Latin to Middle French, including Caesar's Gallic Wars which was published in Paris in 1485 by Antoine Vérard, works from the third decade of Titus Livius, and Giovanni Pico della Mirandola's Conseils prouffitables contre les ennuis et tribulations du monde in 1498. He translated Alain Chartier's Curial into Latin from Middle French in 1473.
- Epistole et orationes
- Rerum gallicarum annales, History of France
- Chronicle of the General Ministers of the Order of the Holy Trinity.
- Robert Gaguin wrote a biography, now lost, of Isabella of Portugal, Duchess of Burgundy, the benefactress of the convent of Préavin
- Encyclopædia Britannica, Humanism, The French humanists, 2008 O.Ed.
- Louis Thuasne (ed.), Roberti Gaguini Epistole et orationes, Paris, Bibliothèque littéraire de la Renaissance, Émile Bouillon, 1903
- Sylvie Charrier, Recherches sur l'oeuvre latine en prose de Robert Gaguin (1433-1501), Paris, H. Champion, 1996.
- Franck Collard, Un historien au travail à la fin du XVe siècle: Robert Gaguin, Geneva, Droz (Travaux d'humanisme et Renaissance, CCCI), 1996.
- Robert Gaguin at the Encyclopédie Universalis (in French)