Réginald Marie Garrigou-Lagrange (French: [ga?igu lagr?~?]; 21 February 1877 – 15 February 1964) was a French Catholic theologian and Dominican friar.
He has been noted as a leading neo-Thomist of the 20th century, along with Jacobus Ramírez, Édouard Hugon, and Martin Grabmann.
He taught at the Dominican Pontifical University of St.
Thomas Aquinas, the Angelicum, in Rome from 1909 to 1960.
There he wrote his magnum opus, The Three Ages of the Interior Life (Les Trois Ages de la Vie Interieure) in 1938.
In 1918 Garrigou initiated courses in sacred art, mysticism, and aesthetics at the Angelicum influencing future liturgical artists such as Marie Alain Couturier, who studied theology there from 1930 to 1932.